A NATURALIST IN BRAZIL 



for certain ants, while little protuberances situated on the tips 

 of the pinnate leaves are eaten by the insects. And the leaves of 

 certain species of Melastomaceae — of whose handsome foliage, 

 brightly variegated, or covered with a symmetrical network of 

 veins, I have already spoken — have developed two bladder-like 

 dilatations on the upper side of the leaves, provided with correspond- 

 ing openings on the under side (Fig. 32, right). These "Ant-pouches" 

 serve as a dwelling for a small, irritable species of ant; perhaps 

 these guests protect the plants against certain enemies; but the 

 problem awaits further examination. 



Some 450 species of ants are known in Brazil ; one encounters ants 



at every step; they are found under almost 

 every stone, and are far more plentiful than in 

 Europe. 



In Brazil, too, the Ants are all the more 

 conspicuous in that certain species, like the Bees 

 and Termites, build plainly-visible nests in trees. 

 The material of such nests is a tough paper, 

 consisting of wood-fibres and triturated wood, 

 consolidated by means of a fluid secreted by 

 the glands of the upper jaw. These again are 

 Aztec ants ; but quite a number of other species 

 make nests of papier-mache, sometimes brittle 

 and woody, sometimes thin as paper, and elastic, 

 according to the proportions of the woody 

 material and the adhesive substance. There are 

 even species which utilize the dung of cows and 

 horses in building their nests. 



These nests often look like great tumours on 

 the bark, and they are sometimes of consider- 

 able size. The nest of the Beard Aztec looks 

 like a giant's beard. It hangs from the boughs 



in a great mass of long tubes, and presents a most curious spectacle 



(Fig. 33)- 



Certain ants make their nests of living leaves, still growing natur- 

 ally on their twigs. These ants approach the site of their intended 

 nest in company. They take up their positions in an orderly row 

 on the edge of a leaf, and all together grasp the edge of the opposing 

 leaf, drawing it up to the leaf to which they are clinging. If the 

 320 



Fig. 33. — Tubular 

 nest of the Beard 

 Aztec. Beneath, a 

 Capy vara or Water- 

 Pig 



