Insect Mushroom-Growers. 



29 



off by another relay of workers ; but, generally, each marches off with the piece 

 it has operated upon, and as all take the same road to their colony, the path they 

 follow becomes in a short time smooth and bare, looking like the impression of 

 a cartwheel through the herbage." 



Bates had not been able to discover for what purj)ose the leaf-cutters 

 went to all this trouble. He thought he had found the reason, and supposed 

 the leaves were gathered for thatching the entrances to their underground 

 cities. In this surmise, however, he was wrong, as Belt and Fritz Miiller 

 have shown. The leaves are taken down and packed in underground 



Mushroom-growing Ants. 



i_By 1 heo. Carrcras. 



The leaf-cutting sauba ants of South and Central America ascend trees in great numbers and frequently strip them of their leaves. 

 These are cut up into small fragments and packed into special chambers, where they ferment and in time produce a crop of small 

 mushrooms. The ants are here shown returning laden after stripping a tree. 



chambers, where they ferment and decay, forming a sort of leaf-mould in 

 which the ants grow mushrooms ! But why ? The saiiba or leaf-cutter is a 

 mycophagist ! It might be argued that there is no reason wli\- the ants should 

 do this, as there are i)l('nt\- of naturally-grown fungi in the forests upon 

 which they could feed, without going to the trouble of gathering leaves and 

 preparing their own mushroom beds from tluiii. True, but the naturally- 

 grown mushrooms are seasonal, and their appearance is modified by fluctuations 

 of temperature and humidity. The human mushroom-cultiwator has discovered 

 that, by preparing suitable beds in dark i)la((> where he can control the 

 temperature, he can have continuous crops ; but tlie saiiba was before him 

 in making this discovery. 



