this liquid at will. This is their secret. A branch of a thistle was covered with brown ants and plant-lice. I observed the latter for some time, so as to discover, if possible, the moment when they caused this secretion to issue from their bodies; but I remarked that i it very rarely came out of its own accord, and that the plant-lice, • which were at some distance from the ants, squirted it out with a: movement resembling a kick. " How did it happen, then, that the ants wandering about on the thistle were nearly all remarkable for the size of their abdomens, and were evidently full of some liquid? This I discovered by narrowly watching one ant, whose proceedings I am going to describe minutely.: I saw it at first passing, without stopping, over some plant-lice, which did not seem in the least disturbed iDy its walking over them; but it soon stopped close to one of the smallest, which it seemed to coax with its antennae, touching the extremity of its abdomen very rapidly,', first with one of its antennae and then with the other. I saw with: surprise the liquid come out of the body of the plant-louse, and the ant forthwith seize upon the droplet and convey it to its mouth. It then brought its antennae to bear upon another plant-louse, much larger than the first; this one, caressed in the same manner, yielded the nourishing fluid from its body in a much larger dose. The ant advanced and took possession of it. It then passed to a third, which it cajoled as it had the preceding ones, giving it many little strokes with its antennae near the hinder extremity of its body; the liquid came out immediately, and the ant picked it up A

small number of these repasts are sufficient to satisfy the ant's appetite. (See Fig. 91.) " It does not appear that it is out of importunity that these insects obtain their nourishment from the plant-lice. " The neighbourhood of ants is agreeable to plant-lice, since those which could get out of the way of their visits, viz., the winged plant-lice, prefer to remain amongst them, and to lavish upon them the superabundance of their nourishment." *

What we have just related applies not only to the brown {Formica brunnea), but also to the tawny ant {For7nica flava)^ to the ashy black {Formica?iigra), to the fuliginous {Formica fiiliginosa), and to a great many more. The Red Ant {Formica rufa) is singularly adroit in seizing the droplet left it by the plant-louse. According to Pierre Huber, it

"Recherches sur les Mceurs des Fourmis Indigenes," pp. 181 — 186. 'iso. Paris, 1 810.

employs its antennae, which swell somewhat towards their extremities, in conveying this droplet to its mouth, and causes it to enter it by pressing it first on one side, then on the other, using its antennae as if they were fingers. The greater number of ants seek them on those plants on which they usually fix themselves— the lowest herbs, as well as the highest trees. There are some, however, which never leave their place of abode, and never go out to the chase. These are the little ants, of a pale yellow colour, rather transparent, and covered with hairs, which are extremely numerous in our meadows and orchards. These subterranean creatures are very noxious to the farmer. Pierre Huber often wondered how they subsisted, and with what food they could provision themselves, without quitting their gloomy habitations. Having one day turned up the earth of which a habitation was composed, in order to discover if any treasure were to be found stowed away there, he found nothing but plant-lice. Of these the greater number were fixed to the roots of the trees which hung down from the roof of their subterranean nest; others were wandering about among the ants. These latter, moreover, set about milking their nurses, as usual, and with the same success. To verify his discovery, he dug up a great number of nests of the yellow ant, and invariably found aphides in them. So as to study the relations which must exist between these insects, he shut up ants with their friends, the plant-lice, in a glazed box, placing at the bottom of the box, earth, mixed with the roots of some plants, whose branches vegetated outside the box. He watered this ant-hill from time to time, and thus both the animals and the plants found in his apparatus sufficient nourishment.

" The ants," he says, " did not endeavour in the least to make their escape. They seemed to want for nothing, and to be quite content. They tended their larvae and females with the same affection they would have shown in their usual ant-hill; they took great care of the plant-lice, and never did them any harm. These, on the other hand, did not seem to fear the ants; they allowed themselves to be moved about from one place to another, and when they were set down they remained in the place chosen for them by their guardians. When the ants wished to move them to a fresh place, they began by caressing them with their antennae, as if to request them to abandon their roots or to withdraw their trunk from the cavity in which it was inserted; then they took them gently above or below the abdomen with their jaws, and carried them with the same care they would have bestowed on the larvae of their own species. I saw the same ant take three plant-lice in succession, each

bigger than itself, and carry them away into a dark place However, the ants do not always act so gently towards them. When they fear that they may be carried off by ants of another kind, and living near their habitation, or when one opens up too suddenly the turf under which they are hidden, they seize them up in haste and carry them off to the bottom of their little cavern. I have seen the ants of two different ant-hills fighting for their plant-lice. When those belonging to one ants' nest could enter the nest of the others, they took them away from their rightful owners, and often these took possession of them again in their turn; for the ants know well the value of these little animals, which seem made on purpose for them,

— they are the ants' treasures. An ants' nest is more or less rich, according as it is more or less stocked with plant-lice. The plant-lice are its cattle, its cows, its goats. One would never have thought that the ants were a pastoral people! "*

Their hiding in the ants' nest is not voluntary; they are prisoners of war. The ants, after having hollowed out galleries in the midst of roots, make a foray upon the turf, and seize upon plant-lice scattered about here and there, bringing them with them, and collect them together in their nests. The captive insects take their wrongs with patience, and behave like philosophers under this new kind of life. They lavish on their masters, with the best grace in the world, the nutritious juices with which their bodies superabound. Charles Bonnet has stated some real wonders of the cleverness and industry of other ants which also make a provision of plant-lice. " I discovered one day," says he, "a Euphorbia, w^hich supported in the middle of its stem a small sphere, to which it served as the axis. It was a case which the ants had constructed of earth. They issued forth from this by a very narrow opening made in its base,

descended the stem, and passed into a neighbouring ants' nest. I destroyed one part of this pavilion, built almost in the air, so that I might study the interior. It was a little room, the vault-shaped walls of which were smooth and even. The ants had profited by the form of the plant to sustain their edifice. The stalk passed up the centre of the apartment, and for its timber-work it had the leaves. This retreat contained a numerous family of plant-lice, to which the brown ants came peacefully, to make their harvest, sheltered from the rain, the sun, and from other ants. No insect could disturb them; and the plant-lice were not exposed to the attacks of their numerous enemies. I admired this trait of industry; and I was not

" Recherches," &c., pp. 192 — 194.

HEM I PT ERA. 12/

long in finding it again, in a more interesting character, in ants of different species. " Some red ants had built round the foot of a thistle a tube of earth, two inches and a half long by one and a half broad. The

ants' nest was below, and communicated directly with rfie cylinder. 1 took the stalk, with what surrounded it, and all that the cylinder contained. That portion of the stem which was inside the earthen lube was covered with plant-lice. I very soon saw the ants coming out at the opening I had made at the base; they were very much astonished to see daylight at that place, and I saw that they lived there with their larvae. They carried these with great haste to the highest part of the cylinder which had not been altered. In this retreat they were within reach of their plant-lice, and here they fed their young. " In other places many stalks of the Euphorbia laden with plant-lice rose in the very centre of an ant-hill belonging to the brown ants. These insects, profiting by the peculiar arrangement of the leaves of this plant, had constructed round each branch as many little elongated cases; and it was here they came to get their food. J Having destroyed one of these cells, the ants forthwith carried off j into their nests their precious animals; a few days afterwards it was I repaired under my eyes by these insects, and the herd were taken back to their pens. " These cases are not always at a few inches from the ground. I saw one five feet above the soil, and this one deserves also to be described. It consisted of a blackish, rather short tube, which was built round a small branch of the poplar at the point where it left the trunk. The ants reached it by the interior of the tree, which was excavated, and without showing themselves, they were able to reach their plant-lice by an opening which they had made in the base of this branch. This tube was formed of rotten wood, of the vegetable earth of this very tree, and I saw many a time the ants bringing little bits in their mouths to repair the breaches I had made in their pavilion. These are not very common traits, and are not of the number of those which can be attributed to an habitual routine.^""^

One day, Pierre Huber discovered in a nest of yellow ants a cell containing a mass of eggs having the appearance of ebony. They were surrounded by a number of ants, which appeared to be guarding them, and endeavouring to carry them off

Huber took possession of the cell, its inhabitants, and of the

■ P. '* Tr^ite d'Insectologie," &c., pp. iq8- 201,

%2S THE INSECT WORLD.

Fig. 91.— Aphides and Ant (magnified).

little treasure it contained, and placed the whole in a box lid, covered with a piece of glass, so as to be more easily observed. He saw the

ants approach the eggs, pass their tongues in between them, c'e-positing on them a liquid. They seemed to treat these eggs exactly as they would have treated those of their own species; they felt them with their antennae, gathered them together, raised them frequently to their mouths, and did not leave them for an instant. They took them up, and turned them over, and after having examined them with care, they carried them with extreme delicacy into the little box of earth placed near them.* These were not, however, ants' eggs. They were the eggs of aphides. The young which were soon to be hatched were to give to the provident ants a reward for the attentions they had lavished upon them. How wonderful are the life and the habits of the plant-lice, and their relations to ants! But we should be led on too far, if we were to pursue these attractive details.

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