the yellow meadow ant, which lives almost entirely below ground, has become much paler.

The ants may be said almost literally to milk the aphides; for, as Darwin and others have shown, the aphides generally retain the secretion until the ants are ready to receive it. The ants stroke and caress the aphides with their antennæ, and the aphides then emit the sweet secretion.

As the honey of the aphides is more or less sticky, it is probably an advantage to the aphis that it should be removed. Nor is this the only service which ants render to them. They protect them from the attacks of enemies; and not unfrequently even build cowsheds of earth over them. The yellow ants collect the rootfeeding species in their nests, and tend them as carefully as their own young. But this is not all. The ants not only guard the mature aphides, which are useful; but also the eggs of the aphides, which of course, until they come to maturity, are quite useless. These eggs were first observed by our countryman Gould, whose excellent little work on ants' has hardly received the attention it deserves. In this case, however, he fell into error. He states that the queen ant' [he is speaking of Lasius flavus] 'lays three different sorts of eggs, the slave, female, and neutral. The two first are deposited in the spring, the last in July and part of August; or, if the summer be extremely favourable,

An Account of English Ants, by the Rev. W. Gould, 1747

perhaps a little sooner. The female eggs are covered with a thin black membrane, are oblong, and about the sixteenth or seventeenth part of an inch in length. The male eggs are of a more brown complexion, and usually laid in March.'

These dark eggs are not those of ants, but of aphides. The error is very pardonable, because the ants treat these eggs exactly as if they were their own, guarding and tending them with the utmost care. I first met with them in February 1876, and was much astonished, not being at that time aware of Huber's observations. I found, as Huber had done before me, that the ants took great care of these brown bodies, carrying them off to the lower chambers with the utmost haste when the nest was disturbed. I brought some home with me and put them near one of my own nests, when the ants carried them inside. That year I was unable to carry my observations further. In 1877 I again procured some of the same eggs, and offered them to my ants, who carried them into the nest, and in the course of March I had the satisfaction of seeing them hatch into young aphides. M. Huber, however, did not think that these were ordinary eggs. On the contrary, he agreed with Bonnet, that the insect, in a state nearly perfect, quits the body of its mother in that covering which shelters it from the cold in winter, and that it is not, as other germs are, in the egg surrounded by food by means of which it is developed and supported. It is nothing more than an

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asylum of which the aphides born at another season have no need; it is on this account some are produced naked, others enveloped in a covering. The mothers are not, then, truly oviparous, since their young are almost as perfect as they ever will be, in the asylum in which Nature has placed them at their birth.'1

This is, I think, a mistake. I do not I do not propose here to describe the anatomy of the aphis; but I may observe that I have examined the female, and find these eggs to arise in the manner described by Huxley,2 and which I have also myself observed in other aphides and in allied genera. Moreover, I have opened the eggs themselves, and have also examined sections, and have satisfied myself that they are really eggs containing ordinary yelk. So far from the young insect being 'nearly perfect,' and merely enveloped in a protective membrane, no limbs or internal organs are present. In fact, the young aphis does not develop in them until shortly before they are hatched.*

When my eggs hatched I naturally thought that the aphides belonged to one of the species usually found on the roots of plants in the nests of Lasius flavus. To my surprise, however, the young creatures

The Natural History of Ants, by M. P. Huber, 1820, p. 246. 2 Linnean Transactions, 1858.

Philosophical Transactions, 1859.

4 I do not enter here into the technical question of the difference between ova and pseudova. I believe these to be true ova, but the point is that they are not a mere envelope containing a young aphis, but eggs in the ordinary sense, the contents of which consist of yelk, and in which the young aphis is gradually developed.

made the best of their way out of the nest, and, indeed, were sometimes brought out by the ants themselves. In vain I tried them with roots of grass &c.; they wandered uneasily about, and eventually died. Moreover, they did not in any way resemble the subterranean species. In 1878 I again attempted to rear these young aphides; but though I hatched a great many eggs, I did not succeed. In 1879, however, I was more fortunate. The eggs commenced to hatch the first week in March. Near one of my nests of Lasius flavus, in which I had placed some of the eggs in question, was a glass containing living specimens of several species of plant commonly found on or around ants' nests. To this some of the young aphides were brought by the ants. Shortly afterwards I observed on a plant of daisy, in the axils of the leaves, some small aphides, very much resembling those from my nest, though we had not actually traced them continuously. They seemed thriving, and remained stationary on the daisy. Moreover, whether they had sprung from the black eggs or not, the ants evidently valued them, for they built up a wall of earth round and over them. So things remained throughout the summer; but on the 9th October I found that the aphides had laid some eggs exactly resembling those found in the ants' nests; and on examining daisy-plants from outside, I found on many of them similar aphides, and more or less of

the same eggs.

I confess these observations surprised me very much.

The statements of Huber, though confirmed by Schmarda, have not, indeed, attracted so much notice as many of the other interesting facts which they have recorded; because if aphides are kept by ants in their nests, it seems only natural that their eggs should also occur. The above case, however, is much more remarkable. Here are aphides, not living in the ants' nests, but outside, on the leaf-stalks of plants. The eggs are laid early in October on the food-plant of the insect. They are of no direct use to the ants, yet they are not left where they are laid, exposed to the severity of the weather and to innumerable dangers, but brought into their nests by the ants, and tended by them with the utmost care through the long winter months until the following March, when the young ones are brought out and again placed on the young shoots of the daisy. This seems to me a most remarkable case of prudence. Our ants may not perhaps lay up food for the winter; but they do more, for they keep during six months the eggs which will enable them to procure food during the following summer, a case of prudence unexampled in the animal kingdom.

The nests of our common yellow ant (Lasius flavus) contain in abundance four or five species of aphis, more than one of which appears to be as yet undescribed. In addition, however, to the insects belonging to this family, there are a large number of others which live habitually in ants' nests, so that we may truly say that our English ants possess a much greater variety of