WITH ARMY ANTS 217 



ply kicked out blindly and brought up against 

 the sandy walls. 



If leaf -cutting ants had been at work here, 

 there would have been a certain amount of co- 

 operation. Certain ones would have cut leaves, 

 other individuals would have picked them up 

 and transported them. But with the army ants 

 this mutual assistance was sublimated, devel- 

 oped to a quintessence of excellence. If I, 

 seated on the rim, overlooking the whole, had 

 been an all-powerful spirit, gifted with the 

 ability to guide by thought simultaneously all 

 the ants within sight, such guidance could not 

 have bettered the cunning cooperation, the unex- 

 pectedly clever anticipation of trouble, the mar- 

 velous singleness of purpose and manifold effec- 

 tiveness exhibited by these astounding creatures. 



First, as to the personnel of the army ants. 

 Roughly I divided them into two categories, 

 white-heads and black-heads. The latter were 

 by far the more numerous and, as a rule, were 

 smaller, with less powerful jaws. But this did 

 not mean that the white-heads were all soldiers. 

 Most of them indeed were the hardest workers. 

 Between the great extremes of size in each of 

 these two types, there seemed to exist only a 



