334 



ANTS. 



ccpnnts ( Fig. iSSi, being yellowish, compact, irregularly polygonal or 

 pyriform bodies, .25-. 55 mm. in diameter, and consisting of elliptical 

 cells much like those of the yeast plant ( ' Saccharoin yccs ). To this 

 fungus I have given the name Tyriiiioinyccs fonnicaniin. C. iclicclcri 

 ( Fig. 186, /; ) is a nocturnal species which nests under stones on the 

 dry hills of western Texas. It collects small plant slivers and culti- 

 vates on them a flocculent, snow-white mycelium with well-developed 

 "kohlrabi clusters" and "heads," or bromatia and gongylidia, as 1 

 prefer to call these hyphal modifications in this and the other fungi 

 cultivated by the Attii. In both of our species of Cyphomyrmex the 



^ . 



' *"~ - 



-*.,, 



: 







FIG. 201. One of the craters of an Atta le.rana nest; about 



graph by C. G. Hartman.) 



natural size. ("Photo- 



gardens are small (only a few cm. in diameter) and of irregular shape. 

 They are never suspended but lie on the floors of small dilations in the 

 rough earthen galleries of the nest. 



2. Mycetosoritis. Our single species, M. hartinani (Fig. 189), is 

 a small brown ant, which lives in the sand of the Texan post-oak 

 woods. Here it builds small craters, the openings of which run down 

 vertically into the sand to a depth of 24-79 cm., suddenly dilating at 

 long intervals into two to four subspherical chambers, which vary 

 from 1.3-3.4 cm. in diameter (Figs. 190 and 191). As a rule, these 

 chambers, which are thus strung along the gallery like beads on a 

 thread, increase in size with the depth. While excavating their 

 chambers the ants leave the rootlets of plants dangling into them as 

 suspensoria for their fungus gardens. These consist of flower anthers 



