No. 417.] NESTS OF AMERICAN ANTS. 717 
social parasite, and for the American Zpaews pergandei, since 
these forms have become so extremely dependent on ants of 
other species that they have even lost the worker caste, thus 
leaving the species to be represented only by the fertile sexes 
like the vast majority of living organisms. The following con- 
densed account of the work of European observers on Anergates 
atratulus is translated from Janet (97, p. 58 e seg.), who inci- 
dentally adds to it some valuable observations of his own : 
Anergates atratulus is a very bizarre ant, which inhabits cen- 
tral and northern Europe. It has been studied by Schenck (52), 
Fic. 18. — Leptothorax curvispinosus Mayr. Worker. 
von Hagens (67), Forel (74), Adlerz ('86), and Wasmann (91). 
As indicated by its name, it is a species which possesses no 
Worker form. At the time of hatching from the pupa the 
