ANTS. 







genera of Attii belong to different species of fungi, for it is very prob- 

 able that the ants of one species would avoid fungus taken from the 

 nest of another on account of the alien nest-aura. Certainly, to the 

 human olfactories, the fungus gardens of Atta te.vana have a very 



striking odor which is al- 

 together lacking in the gar- 

 dens of Tracliymyruic.v, 

 and it would be strange if 

 these differences did not 

 affect the appetites of such 

 sensitive insects as the 

 ants. In my opinion, it is 

 not improbable that the 

 fungi cultivated by the ants 

 may be more closely re- 

 lated to the moulds (As- 

 comycetes ) than to the 

 mushrooms (Basidiomy- 

 cetes). Moeller does, in 

 fact, call attention to cer- 

 tain Ascomycete peculiari- 

 i ties in the mycelium culti- 

 i vated by Aero in y r in c .r 

 discigera. This is a mat- 

 ter, however, to be settled 

 by the mycologist, and I 

 merely call attention to it 

 in this connection, be- 

 cause Moeller's somewhat 

 guarded statements have 

 assumed an unduly positive form in subsequent reviews of his work. 

 The species of Apterostigma investigated by Moeller usually nest in 

 cavities in rotten wood which is often also inhabited by other insects. 

 The fine wood castings and excrement of these insects are used by the 

 ants as material with which to construct their fungus-gardens. A. 

 \'<isinunni constructs the largest nests, and it is onlv in the gardens of 



O / 



this species that the mycelium produces structures analogous to the 

 "kohlrabi heads" and "clusters" of Acromynnc.r. The "heads," 

 however, are club-shaped instead of spherical dilations of the hyphse. 

 The gardens of pilosiun, moclleri and of another undetermined 

 Apterostigma. which live in feeble colonies of only twelve to twenty 

 individuals, are suspended from the roofs of the small cavities, 3 to 4 



j/ -,c.3u 



FIG. 196. Diagram of a large nest of a 

 southern variety of Trachymyrmex septentrio- 

 nalis, showing near the surface the small original 

 chamber of the queen, five chambers with pen- 

 dent fungus gardens, and a newly excavated 

 chamber in which the garden has not yet been 

 started. (Original.) 



