cochineal insect which belongs to this family is called Coccus cacti. It is found in Mexico on the nopal, or prickly pear, and it is said that they are always accompanied by ants.

I

Some ants are omnivorous, e.g. Myrmica lævinodis, which is a common ant in Stonehouse; my vicarage garden abounds with it. I have seen it feasting in the yellow blossom of the buttercup, on the crimson petals of the rhododendron, and on the tender buds of the yucca. have noticed it milking its cows, and holding high festival on the dead body of the green linnet. The Formica rufa I have noticed bearing off insects wherewith to replenish its larder, and visiting trees for the purpose of milking its kine. A bird or a rat thrown upon its heaped-up nest will soon be devoured by the myriads of its inhabitants, who leave nothing but a skeleton as if prepared for an anatomical

museum.

The common garden ant, Formica nigra (Lasius niger), is omnivorous, as may be gathered from what has already been narrated. It delights to milk its cows, and it luxuriates in larvæ in fine condition. The Myrmica domestica (Diplorhoptrum domesticum) also, the pest of many a London house, as it is often reckoned, yet renders friendly service, for while it rejoices in almonds and sugar, it considers a cockroach a delicacy.

The Madeira ant, Tapinoma gracilescens, also, does not object to any kind of food. Sugar is its ordinary diet, yet I have seen it, assisted by a companion, bearing along in triumph, for the benefit of the home circle, many a fine house-fly. The slave-making ant has a taste for animal food as well as a sweet mandible. I have seen it in my formicarium devouring a wasp, as well as sipping at a tray of moistened sugar; and in its native haunts I have seen it hurrying along with a rare beetle, Canopsis fusirostris, a dainty meal, to tempt the appetite of the old folks at home. Into the extraordinary history of this interesting species of ant I propose to enter in the next chapter.

CHAPTER XV.

The slave-makers-How Formica sanguinea may be distinguished from Formica rufa-The author's visits to Shirley Common in search of the Formica sanguinea-Discovery of a nest-The slaves— Other species of ants besides F. fusca found in the slave-maker's nest-The workers, males, and females of the slave-makers described.

THOUGH it is twenty years since I commenced the study of ants, it was not till 1877 that I discovered the habitat of Formica sanguinea-the slave-maker. In 1876 I visited Weybridge, where it used to be abundant, and though I followed strictly the explicit directions of Mr. F. Smith, I did not find sanguinea at home. Formica rufa, the common wood-ant, I found in abundance, but not the slave-maker. Formica sanguinea is very similar in its general appearance to Formica rufa, and it may easily be taken for it by the uninitiated, especially the small workers.

There is, however, a distinct, well-defined characteristic, by which Charles Darwin identified the species, and with which characteristic he was furnished by Mr. Smith, who also pointed it out to me, and which enabled me to distinguish it from any number of F. rufa. While describing the construction of an ant's mouth, I mentioned that the upper lip, or labrum, is protected by its shield, the clypeus. The clypeus extends from beneath the frontal area (see a, in Fig. 296), a triangular plate at the insertion. of the antennæ, to the upper lip, which it conceals. Now

FIG. 29.-Formica sanguinea. a, worker; b, head of ditto.

a-1, scape, and 2, flagellum of antenna; 3, lateral eyes; 4, ocelli; 5, prothorax ; 6, mesothorax; 7, metathorax; 8, coxa; 9, trocanter; 10, femur; 11, tibia; 12, b-1, scape, and 2, flagellum of antenna; 3, lateral eyes; 4, ocelli; a, frontal area; B, emarginate clypeus.

tarsus.

the, anterior margin of this clypeus is distinctly emarginate in F. sanguinea-i.e. instead of having an even edge, and lightly keeled, as in F. rufa, it is decidedly notched. (See Fig. 28, B.)

Furnished with this unfailing characteristic, I started from London on June 5, 1877, in search of the slave-maker, being supplied also with a plan of Shirley Common and its neighbourhood, whither I was bound; and on the plan sketched by Mr. Smith were two spots indicated, where he assured me I should be certain to find sanguinea. I soon reached Croydon by rail, and lost no time in hastening past well-kept gardens bright with rhododendron and scarlet may, through open fields, to the first spot indicated, between Croydon and Shirley, at the stump of an old oak-tree. I searched most carefully, but, alas! in vain. Sanguinea had either migrated or become extinct. I went forward and reached the elevated common-a lovely piece of broken ground, covered with heather and fern and gorse, studded here and there with the aromatic and picturesque Scotch firs, fringed with the tender green of umbrageous oak, elegant silver birch, and other deciduous trees, and commanding an extensive view of a well-wooded, undulating country; and full of hope that my search after sanguinea would be crowned with the much-coveted success, I examined and re-examined the second spot in my plan indicated as its habitat. At the very spot I found what might surely prove to be the little people I longed to meet with. I brought my lens to bear upon the clypeus of many, but, alas! they proved to be members of a somewhat extensive colony of Formica rufa, every one.

Having now lost all clue to the object of my search, I returned to London. Nothing daunted, I presented myself again at the British Museum and received fresh instructions from my kind friend, and a third habitat was explicitly described; and on June 9 I again sallied forth, sustained with a new hope and fired by a fresh enthusiasm. Once

more I reached Shirley Common, and hurried to the dry ditch and its associated bank, where I was assured the slave-maker had established itself in strong force, and this time my patience and perseverance were most happily rewarded. My attention was soon arrested by ants of an unusual appearance and peculiar gait traversing the ground with wondrous expedition, and I felt sure I must be within the charmed circle of sanguinea's domain. The head and thorax, of a blood-red colour, attracted me, and with a confident assurance that I had at last realised the desire of my heart, I seized one of the little creatures with the utmost tenderness and care, and scrutinised it through my lens, and oh the joy of that moment I am utterly unable to describe. The clypeus is emarginate; the unfailing characteristic is clearly revealed to my wondering gaze. I see another, and another, and another. They come thick and fast, and I trace them to a stump of an old gorse bush.

After identifying the species around the gorse stump, on the sunny bank at Shirley, I watched it more closely, and was gratified in finding it very numerously represented in this locality. The ants abounded and were in constant motion; and how were they occupied? Wondrous to relate, two of the workers were carrying each a black ant, called Formica fusca. And I watched also individuals of Formica fusca on most friendly terms with those of Formica sanguinea, going in and coming out of the entrances of a common domicile, while workers of sanguinea were busily and laudably engaged in replenishing the larder, one carrying a beetle, of a very rare species, and which I presented to Mr. Smith, since he had not a representative in his collection. Two other workers carried between them a caterpillar, which would form, doubtless, a most delicious banquet for the hungry inmates of the formic castle. A worker of Formica fusca was carrying material for either the repair or the enlargement of the messuage.

I had thus furnished me unmistakable evidence that