A NATURALIST IN BRAZIL 



as our cabbages and cauliflowers are products of human agriculture. 

 For as soon as the ants are prevented from gaining access to their 

 sponges of mycelium the "kohlrabis" disappear, and the fungus puts 

 forth long aerial filaments, so that the whole mass has a mildewed 

 appearance. Moller has actually shown that the fungus will produce 

 pinkish hat-shaped toadstools, about as tall as one's finger, very like 

 an ordinary mushroom. The ants, however, prevent the outgrowth 

 of filaments by constantly biting them off as they sprout ; a task 

 to which the smallest of the Sauvas have to devote themselves night 

 and day. And they have also to see to the extermination of "weeds." 

 For with every scrap of leaf a host of other spores — as one calls the 

 reproductive corpuscles of the fungus — are introduced into the nest ; 

 and all these must be carefully removed. When the heap of leaf- 

 mould has lost its nutritive properties it is torn out of the mushroom- 

 bed bit by bit, while the gaps are filled up with fresh masses of 

 triturated leaves. Even the outer aspect of a Sauva nest is enough 

 to show that the ants are never idle ; into one hole wanders a pro- 

 cession of workers, each bearing a scrap of green leaf, and from 

 another emerges an equally unbroken chain of workers who throw 

 the debris of exhausted leaf-mould on to rubbish-heaps ; a spectacle 

 which always puts one in mind of a mine or a smelting works, where 

 debris is constantly being cast away. 



The mushroom-nurseries are the actual dwelling-rooms of the 

 Sauvas, and the "kohlrabis" are their only nourishment. When I 

 have been investigating a Sauvas' nest I have always emptied out 

 the whitish sponge-like masses and looked through them, for in them 

 I have found all the forms of workers, the white, maggot-like, shiny 

 larvae, and the equally white pupae, in which one can already 

 recognize the whole formation of the ant. In the mushroom-nurseries 

 the workers pluck the "kohlrabis," eat them themselves, and feed 

 the larvae — or other ants which have so much to do that they have 

 no time to feed themselves. This the ants do by regurgitating the 

 food, masticated and mixed with saliva, into the mouths of other 

 ants. In addition to their own stomach, these creatures actually 

 possess a "social crop" ! This is the first to be filled when they eat, 

 although they derive no profit from it, for it is used only for feeding 

 others. Only when they have accomplished this, their first of duties, 

 do they open a valve between the two stomachs, when the social 

 crop allows a Httle food to fall into the personal stomach ; and only 

 then can it be digested by the ant itself With their social stomachs 

 the ants put the most enthusiastic Socialists to shame ! 

 306 



