600 THE TROPICAL WORLD. 



tened cylinders and compressed cones. A third species, still more ingenious, con- 

 structs its domicile out of a large leaf, bending the two halves by the weight of united 

 millions till the opposite margins meet at the under surface of the mid-rib, where they 

 are secured by a gummy matter. The stores and larvae are conveyed into the nest so 

 made by regular beaten tracks along the trunk and branches of the tree. 



On the large plains near Lake Dilolo, where water stands so long annually as to 

 allow the lotus and other aqueous plants to come to maturity, Livingstone had occa- 

 sion to admire the wonderful sagacity of the ants, whom he declares to be wiser than 

 some men, as they learn by expellee. When all the ant horizon is submerged a foot 

 deep, they manage to exist by ascending to little houses, built of black tenacious loam, 

 on stalks of grass, and placed higher than the line of inundation. This must have 

 been the result of experience, for if they had waited till the water actually invaded 

 their habitations on the ground, they would not have been able to procure materials 

 for their higher quarters, unless they dived down to the bottom for every mouthful of 

 clay. Some of these upper chambers are about the size of a bean, and others as large 

 as a man's thumb. 



Two species of continental Europe, the Formica rubescens and sanguined, are 

 remarkable or infamous for their slave-making expeditions. Unable or unwilling to 

 work themselves, they make war upon others for the sole purpose of procuring bonds- 

 men, who literally and truly labor for them, and perform all the daily domestic duties 

 of the community. 



The Aphides, or plant-lice, eject a sweet, honey-like fluid, which may be correctly 

 termed their milk, and which is so grateful to the ants, that they attend on the honey- 

 flies for the sole purpose of gathering it, and literally milk them as we do our cows, 

 forcing them to yield the fluid, by alternately patting them with their antennae. But 

 the most extraordinary part of these proceedings is, that the ants not only consider the 

 Aphides as their property, but actually appropriate to themselves a certain number, 

 which they enclose in a tube of earth or other materials near their nest, so that they 

 may be always at hand to supply the nourishment which they may desire. The yellow 

 ant, the most remarkable " cow-keeper " among our indigenous species, pays great 

 attention to its herds, plentifully supplying them with proper food, and tending their 

 young with the same tenderness which it exhibits towards its own. With the same 

 provident care a large black ant of India constructs its nest at the root of the plant 

 upon which its favorite species of aphis resides. The ants of tropical America, where 

 no Aphides are found, derive their honey from another family of insects, the numerous 

 and grotesquely-formed Membracidae, which are most abundant in the regions of Bra- 

 zil. According to Mr Swainson, many of these little Membracidae live in families of 

 twenty or thirty, all clustered together on the panicles of grasses, and on the tops of 

 other plants, like the European plant-lice. These are regularly visited by parties of 

 a little black ant, which may be seen going and coming to their heads, and attending 

 them with the same care which the European ants bestow on the Aphides. To render 

 the similarity with cattle still more complete, the Membracidae possess horns growing 

 out of their heads, or are otherwise armed, while their large abrupt heads remind the 

 entomologist of the bull or cow. The Mexican honey ants (Myrmecocystus Mexica- 

 nus) are, if possible, still more remarkable, for here we see an animal rearing others 

 of the same species for the purpose of food. Some of these ants are mainly distin- 



