294 



METAZOAN PHYLA 



queen and be cared for by the workers. In some bumblebee societies 

 there are workers of different sizes, as well as queens and drones. The 



Fig. 192. — Polymorphism as illustrated in an ant, Pheidole instahilis Emery, a, 



soldier; b to c, intermediate types between soldier and worker; /, typical worker; g, 



dealated female, h, male. Much enlarged. {From Wheeler, "Ants." by the courtesy of 

 Columbia University Press.) 



bumblebee performs a very important service in cross-fertilizing the red 

 clover, which in many parts of this country is an important hay crop but 



