THE TACHYTES





The family of Wasps whose name I inscribe at the head of this chapter has

not hitherto, so far as I know, made much noise in the world. Its annals

are limited to methodical classifications, which make very poor reading.

The happy nations, men say, are those which have no history. I accept this,

but I also admit that it is possible to have a history without ceasing to

be happy. In the conviction that I shall not disturb its prosperity, I will

try to substitute the living, moving insect for the insect impaled in a

cork-bottomed box.



It has been adorned with a learned name, derived from the Greek Tachytes,

meaning rapidity, suddenness, speed. The creature's godfather, as we see,

had a smattering of Greek; its denomination is none the less unfortunate:

intended to instruct us by means of a characteristic feature, the name

leads us astray. Why is speed mentioned in this connection? Why a label

which prepares the mind for an exceptional velocity and announces a race of

peerless coursers? Nimble diggers of burrows and eager hunters the Tachytes

are, to be sure, but they are no better than a host of rivals. Not the

Sphex, nor the Ammophila, nor the Bembex, nor many another would admit

herself beaten in either flying or running. At the nesting-season, all this

tiny world of huntresses is filled with astounding activity. The quality of

a speedy worker being common to all, none can boast of it to the exclusion

of the rest.



Had I had a vote when the Tachytes was christened, I should have suggested

a short, harmonious, well-sounding name, meaning nothing else than the

thing meant. What better, for example, than the term Sphex? The ear is

satisfied and the mind is not corrupted by a prejudice, a source of error

to the beginner. I have not nearly as much liking for Ammophila, which

represents as a lover of the sands an animal whose establishments call for

compact soil. In short, if I had been forced, at all costs, to concoct a

barbarous appellation out of Latin or Greek in order to recall the

creature's leading characteristic, I should have attempted to say, a

passionate lover of the Locust.



Love of the Locust, in the broader sense of the Orthopteron, an exclusive,

intolerant love, handed down from mother to daughter with a fidelity which

the centuries fail to impair, this, yes, this indeed depicts the Tachytes

with greater accuracy than a name smacking of the race-course. The

Englishman has his roast-beef; the German his sauerkraut; the Russian his

caviare; the Neapolitan his macaroni; the Piedmontese his polenta; the man

of Carpentras his tian. The Tachytes has her Locust. Her national dish is

also that of the Sphex, with whom I boldly associate her. The methodical

classifier, who works in cemeteries and seems to fly the living cities,

keeps the two families far removed from each other because of

considerations and attaching to the nervures of the wings and the joints of

the palpi. At the risk of passing for a heretic, I bring them together at

the suggestion of the menu-card.



To my own knowledge, my part of the country possesses five species, one and

all addicted to a diet of Orthoptera. Panzer's Tachytes (T. Panzeri, VAN

DER LIND), girdled with red at the base of the abdomen, must be pretty

rare. I surprise her from time to time working on the hard roadside banks

and the trodden edges of the footpaths. There, to a depth of an inch at

most, she digs her burrows, each isolated from the rest. Her prey is an

adult, medium-sized Acridian (Locust or Grasshopper.--Translator's Note.),

such as the White-banded Sphex pursues. The captive of the one would not be

despised by the other. Gripped by the antennae, according to the ritual of

the Sphex, the victim is trailed along on foot and laid beside the nest,

with the head pointing towards the opening. The pit, prepared in advance,

is closed for the time being with a tiny flagstone and some bits of gravel,

in order to avoid either the invasion of a passer-by or obstruction by

landslips during the huntress' absence. A like precaution is taken by the

White-banded Sphex. Both observe the same diet and the same customs.



The Tachytes clears the entrance to the home and goes in alone. She

returns, puts out her head and, seizing her prey by the antennae,

warehouses it by dragging backwards. I have repeated, at her expense, the

tricks which I used to play on the Sphex. (For the author's experiments

with the Languedocian, the Yellow-winged and the White-edged Sphex, cf.

"The Hunting Wasps": chapter 11.--Translator's Note.) While the Tachytes is

underground, I move the game away. The insect comes up again and sees

nothing at its door; it comes out and goes to fetch its Locust, whom it

places in position as before. This done, it goes in again by itself. In its

absence I once more pull back the prey. Fresh emergence of the Wasp, who

puts things to rights and persists in going down again, still by herself,

however often I repeat the experiment. Yet it would be very easy for her to

put an end to my teasing: she would only have to descend straightway with

her game, instead of leaving it for a moment on her doorstep. But, faithful

to the usages of her race, she behaves as her ancestors behaved before her,

even though the ancient custom happen to be unprofitable. Like the Yellow-

winged Sphex, whom I have teased so often during her cellaring-operations,

she is a narrow conservative, learning nothing and forgetting nothing.



Let us leave her to do her work in peace. The Locust disappears underground

and the egg is laid upon the breast of the paralysed insect. That is all:

one carcase for each cell, no more. The entrance is stopped at last, first

with stones, which will prevent the trickling of the embankment into the

chamber; next with sweepings of dust, under which every vestige of the

subterranean house disappears. It is now done: the Tachytes will come here

no more. Other burrows will occupy her, distributed at the whim of her

vagabond humour.



A cell provisioned before my eyes on the 22nd of August, in one of the

walls in the harmas, contained the finished cocoon a week later. (The

harmas was the piece of enclosed waste land in which the author used to

study his insects in their natural state. Cf. "The Life of the Fly," by J.

Henri Fabre, translated by Alexander Teixeira de Mattos: chapter 1.--

Translator's Note.) I have not noted many examples of so rapid a

development. This cocoon recalls, in its shape and texture, that of the

Bembex-wasps. It is hard and mineralized, this is to say, the warp and woof

of silk are hidden by a thick encrustation of sand. This composite

structure seems to me characteristic of the family; at all events I find it

in the three species whose cocoons I know. If the Tachytes are nearly

related to the Spheges in diet, they are far removed from them in the

industry of their larvae. The first are workers in mosaic, encrusting a

network of silk and sand; the second weave pure silk.



Of smaller size and clad in black with trimmings of silvery down on the

edge of the abdominal segments, the Tarsal Tachytes frequents the ledges of

soft limestone in fairly populous colonies. (T. tarsina, LEP.) (According

to M. J. Perez, to whom I submitted the Wasp of which I am about to speak,

this Tachytes might well be a new species, if it is not Lepelletier's T.

tarsina or its equivalent, Panzer's T. unicolor. Any one wishing to clear

up this point will always recognize the quarrelsome insect by its

behaviour. A minute description seems useless to me in the type of

investigation which I am pursuing.--Author's Note.) August and September

are the season of her labours. Her burrows, very close to one another when

an easily-worked vein presents itself, afford an ample harvest of cocoons

once the site is discovered. In a certain gravel-pit in the neighbourhood,

with vertical walls visited by the sun, I have been able within a short

space of time to collect enough to fill the hollow of my hand completely.

They differ from the cocoons of the preceding species only in their smaller

size. The provisions consist of young Acridians, varying from about a

quarter to half an inch in length. The adult insect does not appear in the

assorted bags of game, being no doubt too tough for the feeble grub. All

the carcases consist of Locust-larvae, whose budding wings leave the back

uncovered and put one in mind of the short skirts of a skimpy jacket. Small

so that it may be tender, the game is numerous so that it may suffice all

needs. I count from two to four carcases to a cell. When the time comes we

will discover the reason for these differences in the rations served.



The Mantis-killing Tachytes wears a red scarf, like her kinswoman, Panzer's

Tachytes. (The Mantis-hunting Tachytes was submitted to examination by M.

J. Perez, who failed to recognize her. This species may well be new to our

fauna. I confine myself to calling her the Mantis-killing Tachytes and

leave to the specialists the task of adorning her with a Latin name, if it

be really the fact that the Wasp is not yet catalogued. I will be brief in

my delineation. To my thinking the best description is this: mantis-hunter.

With this information it is impossible to mistake the insect, in my

district of course. I may add that it is black, with the first two

abdominal segments, the legs and the tarsi a rusty red. Clad in the same

livery and much smaller than the female, the male is remarkable for his

eyes, which are of a beautiful lemon-yellow when he is alive. The length is

nearly half an inch for the female and a little more than half this for the

male.--Author's Note.) I do not think that she is very widely distributed.

I made her acquaintance in the Serignan woods, where she inhabits, or

rather used to inhabit--for I fear that I have depopulated and even

destroyed the community by my repeated excavations--where she used to

inhabit one of those little mounds of sand which the wind heaps up against

the rosemary clumps. Outside this small community, I never saw her again.

Her history, rich in incident, will be given with all the detail which it

deserves. I will confine myself for the moment to mentioning her rations,

which consist of Mantis-larvae, those of the Praying Mantis predominating.

(Cf. "The Life of the Grasshopper": chapters 6 to 9.--Translator's Note.)

My lists record from three to sixteen heads for each cell. Once again we

note a great inequality of rations, the reason for which we must try to

discover.



What shall I say of the Black Tachytes (T. nigra, VAN DER LIND) that I have

not already said in telling the story of the Yellow-winged Sphex? ("The

Hunting Wasps": chapters 4 to 6.--Translator's Note.) I have there

described her contests with the Sphex, whose burrow she seems to me to have

usurped; I show her dragging along the ruts in the roads a paralysed

Cricket, seized by the hauling-ropes, his antennae; I speak of her

hesitations, which lead me to suspect her for a homeless vagabond, and

finally on her surrender of her game, with which she seems at once

satisfied and embarrassed. Save for the dispute with the Sphex, an unique

event in my records as observer, I have seen all the rest many a time, but

never anything more. The Black Tachytes, though the most frequent of all in

my neighbourhood, remains a riddle to me. I know nothing of her dwelling,

her larvae, her cocoons, her family-arrangements. All that I can affirm,

judging by the invariable nature of the prey which one sees her dragging

along, is that she must feed her larvae on the same non-adult Cricket that

the Yellow-winged Sphex chooses for hers.



Is she a poacher, a pillager of other's property, or a genuine huntress? My

suspicions are persistent, though I know how chary a man should be of

suspicions. At one time I had my doubts about Panzer's Tachytes, whom I

grudged a prey to which the White-banded Sphex might have laid claim. To-

day I have no such doubts: she is an honest worker and her game is really

the result of her hunting. While waiting for the truth to be revealed and

my suspicions set aside, I will complete the little that I know of her by

noting that the Black Tachytes passes the winter in the adult form and away

from her cell. She hibernates, like the Hairy Ammophila. In warm, sheltered

places, with low, perpendicular, bare banks, dear to the Wasps, I am

certain of finding her at any time during the winter, however briefly I

investigate the earthen surface, riddled with galleries. I find the

Tachytes cowering singly in the hot oven formed by the end of a tunnel. If

the temperature be mild and the sky clear, she emerges from her retreat in

January and February and comes to the surface of the bank to see whether

spring is making progress. When the shadows fall and the heat decreases,

she reenters her winter-quarters.



The Anathema Tachytes (T. anathema, VAN DER LIND), the giant of her race,

almost as large as the Languedocian Sphex and, like her, decorated with a

red scarf round the base of the abdomen, is rarer than any of her

congeners. I have come upon her only some four or five times, as an

isolated individual and always in circumstances which will tell us of the

nature of her game with a probability that comes very near to certainty.

She hunts underground, like the Scoliae. In September I see her go down

into the soil, which has been loosened by a recent light shower; the

movement of the earth turned over keeps me informed of her subterranean

progress. She is like the Mole, ploughing through a meadow in pursuit of

his White Worm. She comes out farther on, nearly a yard from the spot at

which she went in. This long journey underground has taken her only a few

minutes.



Is this due to extraordinary powers of excavation on her part? By no means:

the Anathema Tachytes is an energetic tunneller, no doubt, but, after all,

is incapable of performing so great a labour in so short a time. If the

underground worker is so swift in her progress, it is because the track

followed has already been covered by another. The trail is ready prepared.

We will describe it, for it is clearly defined before the intervention of

the Wasp.



On the surface of the ground, for a length of two paces at most, runs a

sinuous line, a beading of crumbled soil, roughly the width of my finger.

>From this line of ramifications (others) shoot out to left and right, much

shorter and irregularly distributed. One need not be a great entomological

scholar to recognize, at the first glance, in these pads of raised earth,

the trail of a Mole-cricket, the Mole among insects. It is the Mole-cricket

who, seeking for a root to suit her, has excavated the winding tunnel, with

investigation-galleries grafted to either side of the main road. The

passage is free therefore, or at most blocked by a few landslips, of which

the Tachytes will easily dispose. This explains her rapid journey

underground.



But what does she do there? For she is always there, in the few

observations which chance affords me. A subterranean excursion would not

attract the Wasp if it had no object. And its object is certainly the

search for some sort of game for her larvae. The inference becomes

inevitable: the Anathema Tachytes, who explores the Mole-cricket's

galleries, gives her larvae this same Mole-cricket as their food. Very

probably the specimen selected is a young one, for the adult insect would

be too big. Besides, to this consideration of quantity is added that of

quality. Young and tender flesh is highly appreciated, as witness the

Tarsal Tachytes, the Black Tachytes and the Mantis-killing Tachytes, who

all three select game that is not yet made tough by age. It goes without

saying that the moment the huntress emerged from the ground I proceeded to

dig up the track. The Mole-cricket was no longer there. The Tachytes had

come too late; and so had I.



Well, how right was I to define the Tachytes as a Locust lover! What

constancy in the gastronomic rules of the race! And what tact in varying

the game, while keeping within the order of the Orthoptera! What have the

Locust, the Cricket, the Praying Mantis and the Mole-cricket in common, as

regards their general appearance? Why, absolutely nothing! None of us, if

he were unfamiliar with the delicate associations dictated by anatomy,

would think of classing them together. The Tachytes, on the other hand,

makes no mistake. Guided by her instinct, which rivals the science of a

Latreille, she groups them all together. (Pierre Andre Latreille (1762-

1833), one of the founders of entomological science, a professor at the

Musee d'histoire naturelle and member of the Academie des sciences.--

Translator's Note.)



This instinctive taxonomy becomes more surprising still if we consider the

variety of the game stored in a single burrow. The Mantis-killing Tachytes,

for instance, preys indiscriminately upon all the Mantides that occur in

her neighbourhood. I see her warehousing three of them, the only varieties,

in fact, that I know in my district. They are the following: the Praying

Mantis (M. religiosa, LIN.), the Grey Mantis (Ameles decolor, CHARP. (Cf.

"The Life of the Grasshopper": chapter 10.--Translator's Note.)) and the

Empusa (E. pauperata, LATR. (Cf. idem: chapter 9.--Translator's Note.)).

The numerical predominance in the Tachytes' cells belongs to the Praying

Mantis; and the Grey Mantis occupies second place. The Empusa, who is

comparatively rare on the brushwood in the neighbourhood, is also rare in

the store-houses of the Wasp; nevertheless her presence is repeated often

enough to show that the huntress appreciates the value of this prey when

she comes across it. The three sorts of game are in the larval state, with

rudimentary wings. Their dimensions, which vary a good deal, fluctuate

between two-fifths and four-fifths of an inch in length.



The Praying Mantis is a bright green; she boasts an elongated prothorax and

an alert gait. The other Mantis is ash-grey. Her prothorax is short and her

movements heavy. The coloration therefore is no guide to the huntress, any

more than the gait. The green and the grey, the swift and the slow are

unable to baffle her perspicacity. To her, despite the great difference in

appearance, the two victims are Mantes. And she is right.



But what are we to say of the Empusa? The insect world, at all events in

our parts, contains no more fantastic creature. The children here, who are

remarkable for finding names which really depict the animal, call the larva

"the Devilkin." It is indeed a spectre, a diabolical phantom worthy of the

pencil of a Callot. (Jacques Callot (1592-1635), the French engraver and

painter, famous for the grotesque nature of his subjects.--Translator's

Note.) There is nothing to beat it in the extravagant medley of figures in

his "Temptation of Saint Anthony." Its flat abdomen, scalloped at the

edges, rises into a twisted crook; its peaked head carries on the top two

large, divergent, tusk-shaped horns; its sharp, pointed face, which can

turn and look to either side, would fit the wily purpose of some

Mephistopheles; its long legs have cleaver-like appendages at the joints,

similar to the arm-pieces which the knights of old used to bear upon their

elbows. Perched high upon the shanks of its four hind-legs, with its

abdomen curled, its thorax raised erect, its front-legs, the traps and

implements of warfare, folded against its chest, it sways limply from side

to side, on the tip of the bough.



Any one seeing it for the first time in its grotesque pose will give a

start of surprise. The Tachytes knows no such alarm. If she catches sight

of it, she seizes it by the neck and stabs it. It will be a treat for her

children. How does she manage to recognize in this spectre the near

relation of the Praying Mantis? When frequent hunting-expeditions have

familiarized her with the last-named and suddenly, in the midst of the

chase, she encounters the Devilkin, how does she become aware that this

strange find makes yet another excellent addition to her larder? This

question, I fear, will never receive an adequate reply. Other huntresses

have already set us the problem; others will set it to us again. I shall

return to it, not to solve it, but to show even more plainly how obscure

and profound it is. But we will first complete the story of the Mantis-

killing Tachytes.



The colony which forms the subject of my investigations is established in a

mound of fine sand which I myself cut into, a couple of years ago, in order

to unearth a few Bembex larvae. The entrances to the Tachytes' dwelling

open upon the little upright bank of the section. At the beginning of July

the work is in full swing. It must have been going on already for a week or

two, for I find very forward larvae, as well as recent cocoons. There are

here, digging into the sand or returning from expeditions with their booty,

some hundred females, whose burrows, all very close to one another, cover

an area of barely a square yard. This hamlet, small in extent, but

nevertheless densely populated, shows us the Mantis-slayer under a moral

aspect which is not shared by the Locust slayer, Panzer's Tachytes, who

resembles her so closely in costume. Though engaged in individual tasks,

the first seeks the society of her kind, as do certain of the Sphex-wasps,

while the second establishes herself in solitude, after the fashion of the

Ammophila. Neither the personal form nor the nature of the occupation

determines sociability.



Crouching voluptuously in the sun, on the sand at the foot of the bank, the

males lie waiting for the females, to plague them as they pass. They are

ardent lovers, but cut a poor figure. Their linear dimensions are barely

half those of the other sex, which implies a volume only one-eighth as

great. At a short distance they appear to wear on their heads a sort of

gaudy turban. At close quarters this headgear is seen to consist of the

eyes, which are very large and a bright lemon-yellow and which almost

entirely surround the head.



At ten o'clock in the morning, when the heat begins to grow intolerable to

the observer, there is a continual coming and going between the burrows and

the tufts of grass, everlasting, thyme and wormwood, which constitute the

Tachytes' hunting-grounds within a moderate radius. The journey is so short

that the Wasp brings her game home on the wing, usually in a single flight.

She holds it by the fore-part, a very judicious precaution, which is

favourable to rapid stowage in the warehouse, for then the Mantis' legs

stretch backwards, along the axis of the body, instead of folding and

projecting sideways, when their resistance would be difficult to overcome

in a narrow gallery. The lanky prey dangles beneath the huntress, all limp,

lifeless and paralysed. The Tachytes, still flying, alights on the

threshold of the home and immediately, contrary to the custom of Panzer's

Tachytes, enters with her prey trailing behind her. It is not unusual for a

male to come upon the scene at the moment of the mother's arrival. He is

promptly snubbed. This is the time for work, not for amusement. The

rebuffed male resumes his post as a watcher in the sun; and the housewife

stows her provisions.



But she does not always do so without hindrance. Let me recount one of the

misadventures of this work of storage. There is in the neighbourhood of the

burrows a plant which catches insects with glue. It is the Oporto silene

(S. portensis), a curious growth, a lover of the sea-side dunes, which,

though of Portuguese origin, as its name would seem to indicate, ventures

inland, even as far as my part of the country, where it represents perhaps

a survivor of the coastal flora of what was once a Pliocene sea. The sea

has disappeared; a few plants of its shores have remained behind. This

Silene carries in most of its internodes, in those both of the branches and

of the main stalk, a viscous ring, two- to four-fifths of an inch wide,

sharply delimited above and below. The coating of glue is of a pale brown.

Its stickiness is so great that the least touch is enough to hold the

object. I find Midges, Plant-lice and Ants caught in it, as well as tufted

seeds which have blown from the capitula of the Cichoriaceae. A Gad-fly, as

big as a Blue bottle, falls into the trap before my eyes. She has barely

alighted on the perilous perch when lo, she is held by the hinder tarsi!

The Fly makes violent efforts to take wing; she shakes the slender plant

from top to bottom. If she frees her hinder tarsi she remains snared by the

front tarsi and has to begin all over again. I was doubting the possibility

of her escape when, after a good quarter of an hour's struggle, she

succeeded in extricating herself.



But, where the Gad-fly has got off, the Midge remains. The winged Aphis

also remains, the Ant, the Mosquito and many another of the smaller

insects. What does the plant do with its captures? Of what use are these

trophies of corpses hanging by a leg or a wing? Does the vegetable bird-

limer, with its sticky rings, derive advantage from these death-struggles?

A Darwinian, remembering the carnivorous plants, would say yes. As for me,

I don't believe a word of it. The Oporto silene is ringed with bands of

gum. Why? I don't know. Insects are caught in these snares. Of what use are

they to the plant? Why, none at all; and that's all about it. I leave to

others, bolder than myself, the fantastic idea of taking these annular

exudations for a digestive fluid which will reduce the captured Midges to

soup and make them serve to feed the Silene. Only I warn them that the

insects sticking to the plant do not dissolve into broth, but shrivel,

quite uselessly, in the sun.



Let us return to the Tachytes, who is also a victim of the vegetable snare.

With a sudden flight, a huntress arrives, carrying her drooping prey. She

grazes the Silene's lime-twigs too closely. Behold the Mantis caught by the

abdomen. For twenty minutes at least the Wasp, still on the wing, tugs at

her, tugging again and again, to overcome the cause of the hitch and

release the spoil. The hauling-method, a continuation of the flight, comes

to nothing; and no other is attempted. At last the insect wearies and

leaves the Mantis hanging to the Silene.



Now or never was the moment for the intervention of that tiny glimmer of

reason which Darwin so generously grants to animals. Do not, if you please,

confound reason with intelligence, as people are too prone to do. I deny

the one; and the other is incontestable, within very modest limits. It was,

I said, the moment to reason a little, to discover the cause of the hitch

and to attack the difficulty at its source. For the Tachytes the matter was

of the simplest. She had but to grab the body by the skin of the abdomen

immediately above the spot caught by the glue and to pull it towards her,

instead of persevering in her flight without releasing the neck. Simple

though this mechanical problem was, the insect was unable to solve it,

because she was not able to trace the effect back to the cause, because she

did not even suspect that the stoppage had a cause.



Ants doting on sugar and accustomed to cross a foot-bridge in order to

reach the warehouse are absolutely prevented from doing so when the bridge

is interrupted by a slight gap. They would only need a few grains of sand

to fill the void and restore the causeway. They do not for a moment dream

of it, plucky navvies though they be, capable of raising miniature

mountains of excavated soil. We can get them to give us an enormous cone of

earth, an instinctive piece of work, but we shall never obtain the

juxtaposition of three grains of sand, a reasoned piece of work. The Ant

does not reason, any more than the Tachytes.



If you bring up a tame Fox and set his platter of food before him, this

creature of a thousand tricks confines himself to tugging with all his

might at the leash which keeps him a step or two from his dinner. He pulls

as the Tachytes pulls, exhausts himself in futile efforts and then lies

down, with his little eyes leering fixedly at the dish. Why does he not

turn round? This would increase his radius; and he could reach then the

food with his hind-foot and pull it towards him. The idea never occurs to

him. Yet another animal deprived of reason.



Friend Bull, my Dog, is no better-endowed, despite his quality as a

candidate for humanity. In our excursions through the woods, he happens to

get caught by the paw in a wire snare set for rabbits. Like the Tachytes,

he tugs at it obstinately and only pulls the noose tighter. I have to

release him when he does not himself succeed in snapping the wire by his

hard pulling. When he tries to leave the room, if the two leaves of the

door are just ajar, he contents himself with pushing his muzzle, like a

wedge, into the too narrow aperture. He moves forward, pushing in the

direction which he wishes to take. His simple, dog-like method has one

unfailing result: the two leaves of the door, when pushed, merely shut

still closer. It would be easy for him to pull one of them towards him with

his paw, which would make the passage wider; but this would be a movement

backward, contrary to his natural impulse; and so he does not think of it.

Yet another creature that does not reason.



The Tachytes, who stubbornly persists in tugging at her limed Mantis and

refuses to acknowledge any other method of wresting her from the Silene's

snare, shows us the Wasp in an unflattering light. What a very poor

intellect! The insect becomes only the more wonderful, therefore, when we

consider its supreme talent as an anatomist. Many a time I have insisted

upon the incomprehensible wisdom of instinct; I do so again at the risk of

repeating myself. An idea is like a nail: it is not to be driven in save by

repeated blows. By hitting it again and again, I hope to make it enter the

most rebellious brains. This time I shall attack the problem from the other

end, that is, I shall first allow human knowledge to have its say and shall

then interrogate the insect's knowledge.



The outward structure of the Praying Mantis would of itself be enough to

teach us the arrangement of the nerve-centres which the Tachytes has to

injure in order to paralyse its victim, which is destined to be devoured

alive but harmless. A narrow and very long prothorax divides the front pair

of legs from the two hinder pairs. There must therefore be an isolated

ganglion in front and two ganglia, close to each other, about two-fifths of

an inch back. Dissection confirms this forecast completely. It shows us

three fairly bulky thoracic ganglia, arranged in the same manner as the

legs. The first which actuates the fore-legs, is placed opposite their

roots. It is the largest of the three. It is also the most important, for

it presides over the insect's weapons, over the two powerful arms, toothed

like saws and ending in harpoons. The other two, divided from the first by

the whole length of the prothorax, each face the origin of the

corresponding legs; consequently they are very near each other. Beyond them

are the abdominal ganglia, which I pass over in silence, as the operating

insect does not have to trouble about them. The movements of the belly are

mere pulsations and are in no way dangerous.



Now let us do a little reasoning on behalf of our non-reasoning insect. The

sacrificer is weak; the victim is comparatively powerful. Three strokes of

the lancet must abolish all offensive movement. Where will the first stroke

be delivered? In front is a real engine of warfare, a pair of powerful

shears with toothed jaws. Let the fore-arm close upon the upper arm; and

the imprudent insect, crushed between the two saw-blades, will be torn to

pieces; wounded by the terminal hook, it will be eviscerated. This

ferocious mechanism is the great danger; it is this that must be mastered

at the outset, at the risk of life; the rest is less urgent. The first blow

of the stylet, cautiously directed, is therefore aimed at the lethal fore-

legs, which imperil the vivisector's own existence. Above all, there must

be no hesitation. The blow must be accurate then and there, or the

sacrificer will be caught in the vice and perish. The two other pairs of

legs present no danger to the operator, who might neglect them if she had

only her own security to think of; but the surgeon is operating with a view

to the egg, which demands complete immobility in the provisions. Their

centres of innervation will therefore be stabbed as well, with the leisure

which the Mantis, now put out of action, permits. These legs, as well as

their nervous centres, are situated very far behind the first point

attacked. There is a long neutral interval, that of the prothorax, into

which it is quite useless to drive the sting. This interval has to be

crossed; by a backward movement conforming with the secrets of the victim's

internal anatomy, the second ganglion must be reached and then its

neighbour, the third. In short, the surgical operation may be formulated

thus: a first stab of the lancet in front; a considerable movement to the

rear, measuring about two-fifths of an inch; lastly, two lancet-thrusts at

two points very close together. Thus speaks the science of man; thus

counsels reason, guided by anatomical structure. Having said this much let

us observe the insect's practice.



There is no difficulty about seeing the Tachytes operate in our presence;

we have only to resort to the method of substitution, which has already

done me so much service, that is, to deprive the huntress of her prey and

at once to give her, in exchange, a living Mantis of about the same size.

This substitution is impracticable with the majority of the Tachytes, who

reach the threshold of their dwelling in a single flight and at once vanish

underground with their game. A few of them, from time to time, harassed

perhaps by their burden, chance to alight at a short distance from their

burrow, or even drop their prey. I profit by these rare occasions to

witness the tragedy.



The dispossessed Wasp recognizes instantly, from the proud bearing of the

substituted Mantis, that she is no longer embracing and carrying off an

inoffensive carcase. Her hovering, hitherto silent, develops a buzz,

perhaps to overawe the victim; her flight becomes an extremely rapid

oscillation, always behind the quarry. It is as who should say the quick

movement of a pendulum swinging without a wire to hang from. The Mantis,

however, lifts herself boldly upon her four hind-legs; she raises the fore-

part of her body, opens, closes and again opens her shears and presents

them threateningly at the enemy; using a privilege which no other insect

shares, she turns her head this way and that, as we do when we look over

our shoulders; she faces her assailant, ready to strike a return blow

wheresoever the attack may come. It is the first time that I have witnessed

such defensive daring. What will be the outcome of it all?



The Wasp continues to oscillate behind the Mantis, in order to avoid the

formidable grappling-engine; then, suddenly, when she judges that the other

is baffled by the rapidity of her manoeuvres, she hurls herself upon the

insect's back, seizes its neck with her mandibles, winds her legs round its

thorax and hastily delivers a first thrust of the sting, to the front, at

the root of the lethal legs. Complete success! The deadly shears fall

powerless. The operator then lets herself slip as she might slide down a

pole, retreats along the Mantis' back and, going a trifle lower, less than

a finger's breadth, she stops and paralyses, this time without hurrying

herself, the two pairs of hind-legs. It is done: the patient lies

motionless; only the tarsi quiver, twitching in their last convulsions. The

sacrificer brushes her wings for a moment and polishes her antennae by

passing them through her mouth, an habitual sign of tranquillity returning

after the emotions of the conflict; she seizes the game by the neck, takes

it in her legs and flies away with it.



What do you say to it all? Do not the scientist's theory and the insect's

practice agree most admirably? Has not the animal accomplished to

perfection what anatomy and physiology enabled us to foretell? Instinct, a

gratuitous attribute, an unconscious inspiration, rivals knowledge, that

most costly acquisition. What strikes me most is the sudden recoil after

the first thrust of the sting. The Hairy Ammophila, operating on her

caterpillar, likewise recoils, but progressively, from one segment to the

next. Her deliberate surgery might receive a quasi-explanation if we

ascribe it to a certain uniformity. With the Tachytes and the Mantis this

paltry argument escapes us. Here are no lancet-pricks regularly

distributed; on the contrary, the operating-method betrays a lack of

symmetry which would be inconceivable, if the organization of the patient

did not serve as a guide. The Tachytes therefore knows where her prey's

nerve-centres lie; or, to speak more correctly, she behaves as though she

knew.



This science which is unconscious of itself has not been acquired, by her

and by her race, through experiments perfected from age to age and habits

transmitted from one generation to the next. It is impossible, I am

prepared to declare a hundred times, a thousand times over, it is

absolutely impossible to experiment and to learn an art when you are lost

if you do not succeed at the first attempt. Don't talk to me of atavism, of

small successes increasing by inheritance, when the novice, if he

misdirected his weapon, would be crushed in the trap of the two saws and

fall a prey to the savage Mantis! The peaceable Locust, if missed, protests

against the attack with a few kicks; the carnivorous Mantis, who is in the

habit of feasting on Wasps far more powerful than the Tachytes, would

protest by eating the bungler; the game would devour the hunter, an

excellent catch. Mantis-paralysing is a most perilous trade and admits of

no half-successes; you have to excel in it from the first, under pain of

death. No, the surgical art of the Tachytes is not an acquired art. Whence

then does it come, if not from the universal knowledge in which all things

move and have their being!



What would happen if, in exchange for her Praying Mantis, I were to give

the Tachytes a young Grasshopper? In rearing insects at home, I have

already noted that the larvae put up very well with this diet; and I am

surprised that the mother does not follow the example of the Tarsal

Tachytes and provide her family with a skewerful of Locusts instead of the

risky prey which she selects. The diet would be practically the same; and

the terrible shears would no longer be a danger. With such a patient would

her operating-method remain the same; should we again see a sudden recoil

after the first stab under the neck; or would the vivisector modify her art

in conformity with the unfamiliar nervous organization?



This second alternative is highly improbable. It would be nonsense to

expect to see the paralyser vary the number and the distribution of the

wounds according to the genus of the victim. Supremely skilled in the task

that has fallen to its lot, the insect knows nothing further.



The first alternative seems to offer a certain chance and deserves a test.

I offer the Tachytes, deprived of her Mantis, a small Grasshopper, whose

hind-legs I amputate to prevent his leaping. The disabled Acridian jogs

along the sand. The Wasp flies round him for a moment, casts a contemptuous

glance upon the cripple and withdraws without attempting action. Let the

prey offered be large or small, green or grey, short or long, rather like

the Mantis or quite different, all my efforts miscarry. The Tachytes

recognizes in an instant that this is no business of hers; this is not her

family game; she goes off without even honouring my Grasshoppers with a

peck of her mandibles.



This stubborn refusal is not due to gastronomical causes. I have stated

that the larvae reared by my own hands feed on young Grasshoppers as

readily as on young Mantes; they do not seem to perceive any difference

between the two dishes; they thrive equally on the game chosen by me and

that selected by the mother. If the mother sets no value on the

Grasshopper, what then can be the reason of her refusal? I can see only

one: this quarry, which is not hers, perhaps inspires her with fear, as any

unknown thing might do; the ferocious Mantis does not alarm her, but the

peaceable Grasshopper terrifies her. And then, if she were to overcome her

apprehensions, she does not know how to master the Acridian and, above all,

how to operate upon him. To every man his trade, to every Wasp her own way

of wielding her sting. Modify the conditions ever so slightly; and these

skilful paralysers are at an utter loss.



To every insect also its own art of fashioning the cocoon, an art which

varies greatly, an art in which the larva displays all the resources of its

instincts. The Tachytes, the Bembeces, the Stizi, the Palari and other

burrowers build composite cocoons, hard as fruit-stones, formed of an

encrustation of sand in a network of silk. We are already acquainted with

the work of the Bembex. I will recall the fact that their larva first

weaves a conical, horizontal bag of pure white silk, with wide meshes, held

in place by interlaced threads which fix it to the walls of the cell. I

have compared this bag, because of its shape, with a fishtrap. Without

leaving this hammock, stretching its neck through the orifice, the worker

gathers from without a little heap of sand, which it stores inside its

workshop. Then, selecting the grains one by one, it encrusts them all

around itself in the fabric of the bag and cements them with the fluid from

its spinnerets, which hardens at once. When this task is finished, the

house has still to be closed, for it has been wide open all this time to

permit of the renewal of the store of sand as the heap inside becomes

exhausted. For this purpose a cap of silk is woven across the opening and

finally encrusted with the materials which the larva has retained at its

disposal.



The Tachytes builds in quite another fashion, although its work, once

finished, does not differ from that of the Bembex. The larva surrounds

itself, to begin with, about the middle of its body with a silken girdle

which a number of threads, very irregularly distributed, hold in place and

connect with the walls of the cell. Sand is collected, within reach of the

worker, on this general scaffolding. Then begins the work of minor masonry,

with grains of sand for rubble and the secretion of the spinnerets for

cement. The first course is laid upon the fore-edge of the suspensory ring.

When the circle is completed, a second course of grains of sand, stuck

together by the fluid silk, is raised upon the hardened edge of what has

just been done. Thus the work proceeds, by ring-shaped courses, laid edge

to edge, until the cocoon, having acquired half of its proper length, is

rounded into a cap and finally is closed. The building-methods of the

Tachytes-larva remind me of a mason constructing a round chimney, a narrow

tower of which he occupies the centre. Turning on his own axis and using

the materials placed to his hand, he encloses himself little by little in

his sheath of masonry. In the same way the worker encloses itself in its

mosaic. To build the second half of the cocoon, the larva turns round and

builds in the same way on the other edge of the original ring. In about

thirty-six hours the solid shell is completed.



I am rather interested to see the Bembex and the Tachytes, two workers in

the same guild, employ such different methods to achieve the same result.

The first begins by weaving an eel-trap of pure silk and next encrusts the

grains of sand inside; the second, a bolder architect, is economical of the

silk envelope, confines itself to a hanging girdle and builds course by

course. The building-materials are the same: sand and silk; the

surroundings amid which the two artisans work are the same: a cell in a

soil of sandy gravel; yet each of the builders possesses its individual

art, its own plan, its one method.



The nature of the food has no more effect upon the larva's talents than the

environment in which it lives or the materials employed. The proof of this

is furnished by Stiza ruficornis, another builder of cocoons in grains of

sand cemented with silk. This sturdy Wasp digs her burrows in soft

sandstone. Like the Mantis-killing Tachytes, she hunts the various Mantides

of the countryside, consisting mainly of the Praying Mantis; only her large

size requires them to be more fully developed, without however having

attained the form and the dimensions of the adult. She places three to five

of them in each cell.



In solidity and volume her cocoon rivals that of the largest Bembex; but it

differs from it, at first sight, by a singular feature of which I know no

other example. From the side of the shell, which is uniformly smoothed on

every side, a rough knob protrudes, a little clod of sand stuck on to the

rest. The work of Stizus ruficornis can at once be recognized, among all

the other cocoons of a similar nature, by this protuberance.



Its origin will be explained by the method which the larva follows in

constructing its strong-box. At the beginning, a conical bag is woven of

pure white silk; you might take it for the initial eel-trap of the

Bembeces, only this bag has two openings, a very wide one in front and

another, very narrow one at the side. Through the front opening the Stizus

provides itself with sand as and when it spends this material on encrusting

the interior. This strengthens the cocoon; and the cap which closes it is

made next. So far it is exactly like the work of the Bembex. We now have

the worker enclosed, engaged in perfecting the inner wall. For these final

touches a little more sand is needed. It obtains it from outside by means

of the aperture which it has taken the precaution of contriving in the side

of its building, a narrow dormer-window just large enough to allow its

slender neck to pass. When the store has been taken in, this accessory

orifice, which is used only during the last few moments, is closed with a

mouthful of mortar, thrust outward from within. This forms the irregular

nipple which projects from the side of the shell.



For the present I shall not expatiate further upon Stizus ruficornis, whose

complete biography would be out of place in this chapter. I will limit

myself to mentioning its method of constructing strong-boxes in order to

compare it with that of the Bembex and above all with that of the Tachytes,

a consumer, like itself, of Praying Mantes. From this parallel it seems to

me to follow that the conditions of life in which men see to-day the origin

of instincts--the type of food, the surroundings amid which the larval life

is passed, the materials available for a defensive wrapper and other

factors which the evolutionists are accustomed to invoke--have no actual

influence upon the larva's industry. My three architects in glued sand,

even when all the conditions, down to the nature of the provisions, are the

same, adopt different means to execute an identical task. They are

engineers who have not graduated from the same school, who have not been

educated on the same principles, though the lesson of things is almost the

same for all of them. The workshop, the work, the provisions have not

determined the instinct. The instinct comes first; it lays down laws

instead of being subject to them.





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