are black, the callows are drab or yellowish (I'onnica snbscrlcca), 

 while in others they ma\ be orange or deep red (Platythytea pnnctutd ). 

 The callows of bright red ants are often sulphur yellow or orange 

 ( I'olycri/ns. Pogonomyrmex, Mynnica inntica), while in the yellow 

 .species, like our North American Lasius of the stibgenus Acautho- 

 invops, the eallou s are sordid white or drab (Fig. 46, u ) . 



FIG. 46. Acanthomyops cluriger workers and cocoons, X 2. (Photograph by J. 

 <\. Huhliard and Dr. O. S. Strong.) a. Callow workers; b. queen cocoons; remain- 

 in. L; cocoons those of workers. 



The length of embryonic, larval and pupal life appears to be highly 

 variable and to depend very intimately on temperature. Wasmann 

 (i8o,if ) and Miss Fickle (1905(7) have shown that a rise of tempera- 

 ture at once induces both females and workers to lav and accelerates the 



