296 



ENTOMOLOGY 



fungus at length appears. The food for the sake of which the ants 

 carry on their complex operations consists of the knobbed ends of 

 fungus threads (Fig. 292), and these bodies, rich in fluid, form the most 

 important, if not the sole food of the leaf-cutting ants. By assiduously 

 weeding out all foreign organisms the ants obtain a pure culture of the 



fungus, and by pruning the fungus 

 they keep it in the vegetative con- 

 dition and prevent its fructification; 

 under exceptional circumstances, 

 nevertheless, the fungus develops 

 aerial organs of fructification of the 



FIG. 291. A, B, cuts made 

 in Cuphea leaves in four or five 

 minutes by Atta discigera; 

 natural size. 'C, Atta dis- 

 cigera transporting severed 

 fragments of leaves; reduced. 

 After MOLLER. 



FIG. 292. Fungus clumps (Rozites 

 gongylophora) cultivated by ants of the 

 genus Atta. Greatly magnified. After 

 MOLLER. 



agaricine type, but this species (Rozites gongylophora) has never be< 

 found outside of ants' nests. The peculiar clubbed threads we] 

 produced by Moller in artificial cultures and are not spores, but pr< 

 ucts of cultivation. Other ants are known to cultivate other kin< 

 of fungi for similar purposes. 



McCook has found a leaf-cutting ant (A tta fervens) in Texas, am 

 mentions that it cuts circular pieces out of leaves of chiefly the live-oz 

 these being dropped to the ground and taken to the nest by anoth< 

 set of workers. He records an underground tunnel of A tta few 

 which extended 448 feet from the nest and then opened into a path 

 feet in length; the tunnel was 18 inches below the surface on an average, 

 though occasionally as deep as 6 feet, and the entire route led with 

 remarkable precision to a tree which was being defoliated. 



