•1907.] Wheeler, Fungus-grouing Ants of North America. 699 



usurp the functions of the mother ant. They manure the garden, which at 

 the time of their appearance measures hardly more than 2.5 cm. in diameter, 

 and feed the larvae with their mothers' eggs. The workers themselves, 

 however, feed on the "kohlrabi" which has been developing on the hyphae 

 in the meantime. After about a week some of the workers begin to dig in 

 the earth, and ten days after the appearance of the first worker and seven 

 weeks after the inception of the colony, they break through to the surface 

 of the soil and surround the entrance of the nest with a tiny crater of earthen 

 pellets. They now begin to bring in pieces of leaves, knead them up into 

 minute v^ads, and insert them in the fungus gard.Mi. The method of man- 



Fig. 6. Fungus garden of Attn sexdens fourteen days after the nuptial flight. There are 

 about 100 eggs which the queen has placed in a depression in the middle of the garden. Near 

 the periphery there are three drops of the fecal liquid with which the queen manures her garden. 

 (After J. Huber.) 



uring the garden with fecal droplets seems now to be abandoned. The 

 mother Atta henceforth pays no attention to the development of the garden or 

 to the brood, but degenerates into a sluggish egg-laying machine, while the 

 multifarious labors of the colony devolve on the workers. In the meantime 

 the "kohlrabi" has become so abundant that it can be fed to the larvae. In 

 concluding his paper Huber makes the important observation that fertile 

 females of Aifa .se.rden.i are readily adopted In' strange workers of their own 

 species. Such adoptions may be frequently resorted to in a state of nature 

 and would perhaps account for the enormous size and great age of some of 

 the formicaries of the larger species of Atta, which in this respect resemble 

 the colonies of Formica ruja and F. r.rsrrtoidrs- in the north temperate zone. 



