-zoo 



(A) Heterogony of the head in neuter 

 ants; logarithmic plotting. © — ©, 

 Anomma nigricans, head-breadth against 

 abdomen-breadth (in arbitrary units : scale 



below and to the right). H h Cam- 



ponotus gigas, head-weight against total 

 weight, in mg. (scale above and to the 

 left). 



(B) Relative head-size, Anomma nigri- 

 cans. Increase in percentage head-breadth 

 with increase in absolute abdomen-breadth. 

 (In this figure the classes into which the 

 specimens were classified were delimited 

 on the basis of [abdomen-breadth + head- 

 breadth].) 



140 ZOO 



% 



180 



170 



160 



140 



130 



Anomma 

 nigricans 



B 



200 250 300 



cubdomen breadth 



350 



Fig. 37, 



-Graph showing the increase of size of head with absolute size of 

 body in neuter ants. 



64 



