234 
Psyche 
[June 
Fig. 10. Individual ants were ranked according to their relative indices. 
The rank positions (abscissa) are plotted against the index values (ordinate, 
logarithmic). The steepness of the curve directly represents the degree of 
specialization of the worker group. 
Dotted line: Camponoius sericeus ; solid line: Formica sanguinea. 
