xxvi INSECT A : HYMENOPTERA 425 



they form an underground nest with many large well-venti- 

 lated chambers. Then they sally forth and begin to cut 

 large pieces out of the leaves of adjacent trees, carrying 

 these back to the nest, where they 

 are cut up into small pieces, making a 

 loose spongy mass. This is then made 

 to adhere either to the roof or the 

 floor of the chambers, different species 

 of ants having different customs in this 

 matter. The whole mass is soon held 

 together by the white threads (liyphae) 



of a fungus which develops rapidly in 



. i i P i r. . . l ,-, \ i FIG. 319. Five Chambers 



the leaf pulp ; after a time the hyphae from the nest of a Leaf . 



produce at their tips small white cutting Ant in which 

 bodies. It is for the sake of these, ap- tlie white fun s us is 

 parently, that the fungus is cultivated, 

 for they form the only, or at any rate 

 the chief food of the ants ; moreover, it is apparently only 

 when tended by the ants that these little white heads are 

 formed. As soon as the fungus is well developed in the 

 spongy masses, the larvae are distributed throughout it and 

 are fed on it. 



The way in which these fungus-gardens originate in new 

 colonies has recently been brought to light. 1 It has been 

 shown that the young queen, when she goes out for her 

 marriage flight, has always in her infra-buccal pocket (see 

 p, 411) a little pellet of the fungal food, and that when she 

 founds her new colony she ejects this pellet, and with it starts 

 her vegetable garden the day after she enters the earth. On 

 the third day she lays her eggs, and for the next five or 

 six weeks she divides her time between egg-laying, cleaning 

 and nursing the little grubs that hatch out, feeding them 

 on other eggs, and tending her kitchen-garden, apparently 

 watering and manuring the fungus with secretions from her 

 own body. By the time the first batch of workers appears, 

 the fungus is in a condition to be eaten, and it forms their 

 food, though they still feed the larvae on eggs. Finally, 

 about seven weeks after the founding of the colon} 7 , some 

 of the workers make their way out of the earth, and begin 



1 A. von Iherhig, Die Anlage neuer Golonien und Pilzgarten bei Atta 

 sexdens (1898). 



