to October. On one occasion he even observed the ants bringing up their stores of grain to dry them after the closing thunderstorms of the monsoon; an observation which has been since confirmed by other naturalists. It is now known that harvesting ants occur in the warmer part of Europe, where their habits have been observed with care, especially by Moggridge and Lespès. It does not yet seem quite clear in what manner the ants prevent the grains from germinating. Moggridge found that if the ants were prevented from entering the granaries, the seeds began to sprout, and that this was also the case in deserted granaries. It would appear therefore that the power of germination was not destroyed. On the other hand, Lespès confirms the statement long ago made by Pliny that the ants gnaw off the radicle, while Forel asserts that Atta structor allows the seeds in its granaries to commence the process of germination for the sake of the sugar. A Texan ant, Pogonomymex barbatus, is also a harvesting species, storing up especially the grains of Aristida oligantha, the so-called 'ant rice,' and of a grass, Buchla dactyloides. These ants clear disks, ten or twelve feet in diameter, round the entrance to their nest, a work of no small labour in the rich soil, and under the hot sun, of Texas. I say 'clear disks,' but some, though not all, of these disks are occupied, especially round the edge, by a growth of ant rice. These ants were first noticed by Mr. Buckley,' and their habits were some time afterwards described in more detail by Dr. Lincecum,2 who maintained not only that the ground was carefully cleared of all other species of plants, but that this grass was intentionally cultivated by the ants. Mr. McCook,3 by whom this subject has been recently studied, fully confirms Dr. Lincecum that the disks are kept carefully clean, that the ant rice alone is permitted to grow on them, and that the produce of this crop is carefully harvested; but he thinks that the ant rice sows itself, and is not actually cultivated by the ants. I have myself observed in Algeria, that certain species of plants are allowed by the ants to grow on their nests. Proc. Acad. Nat. Sci. Philadelphia, 1860. Linnean Journal, 1861, p. 29. • The Nat. Hist. of the Agricultural Ants of Texas, p. 88. CHAPTER IV. ON THE RELATIONS OF ANTS TO OTHER ANIMALS. THE relations existing between ants and other animals are even more interesting than their relations with plants. As a general rule, not, however, without many remarkable exceptions, they may be said to be those of deadly hostility. Though honey is the principal food of my ants, they are very fond of meat, and in their wild state ants destroy large numbers of other insects. Our English ants generally go out hunting alone, but many of the species living in hotter climates hunt in packs, or even in armies. Savage has given 1 a graphic account of the 'Driver ants (Anomma arcens West.) of West Africa. They keep down, he says, 'the more rapid increase of noxious insects and smaller reptiles; consume much dead animal matter, which is constantly occurring, decaying, becoming offensive, and thus vitiating the atmosphere, and which is by no means the least important in the Torrid Zone, often compelling the inhabitants to keep 14. 'On the Habits of the Driver Ants,' Trane. Ent. Soc. 1847 their dwellings, towns, and their vicinity in a state of comparative cleanliness. The dread of them is upon every living thing. 'Their entrance into a house is soon known by the simultaneous and universal movement of rats, mice, lizards, Blapsidæ, Blattidæ, and of the numerous vermin that infest our dwellings. Not being agreed, they cannot dwell together, which modifies in a good measure the severity of the Drivers' habits, and renders their visits sometimes (though very seldom in my view) desirable. 'They move over the house with a good degree of order, unless disturbed, occasionally spreading abroad, ransacking one point after another, till, either having found something desirable, they collect upon it, when they may be destroyed en masse by hot water. ... "When they are fairly in, we give up the house, and try to await with patience their pleasure, thankful, indeed, if permitted to remain within the narrow limits of our beds or chairs.' These ants will soon destroy even the largest animal if it is confined. In one case Savage saw them kill near his house a snake four feet long. Indeed, it is said that they have been known to destroy the great python, when gorged with food and powerless. The natives even believe that the python, after crushing its victim, does not venture to swallow it, until it has made a search, and is satisfied that there are no Drivers in the vicinity! It is very remarkable that these anting ants are blind. They emerge, however, principally by night, and like some of the blind hunting ants of Brazil (Eciton vastator and E. erratica), well described by Bates, prefer to move under covered gallerier, which they construct rapidly as they advance. The column of foragers pushes forward step by step, under the protection of these covered passages, through the thickets, and on reaching a rotting log, or other promising hunting ground, pour into the crevices in search of booty.' The marauding troops of Ecitons may, in some cases, be described as armies. Wherever they move,' says Bates,2 2the whole animal world is set in commotion, and every creature tries to get out of their way. But it is especially the various tribes of wingless insects that have cause for fear, such as heavy-bodied spiders, ants of other species, maggots, caterpillars, larvæ of cockroaches, and so forth, all of which live under fallen leaves or in decaying wood. The Ecitons do not mount very high on trees, and therefore the nestlings of birds are not much incommoded by them. The mode of operation of these armies, which I ascertained, only after long-continued observation, is as follows: The main column, from four to six deep, moves forward in a given direction, clearing the ground of all animal matter dead or alive, and throwing off, here and there, a thinner column to forage for a short time on the The Naturalist on the River Amazon, vol. ii. p. 364, |