CLASS INSECT A 295 



which will not develop fertile seeds unless there are bumblebees in the 

 region to carry the pollen from one flower to another. 



Wasps and hornets may be distinguished from bees by the possession 

 of jaws instead of suctorial probosces, by the body being smooth and not 

 hairy, and by the legs being never modified for the carrying of pollen. 

 They provision their cells with other animals which they collect and 

 paralyze by stinging before placing them in the cells. Sometimes these 

 cells are provisioned and then sealed, while in other cases the young are 

 fed by the parents as in the case of the bees. The solitary wasps mine 

 in the earth, excavate cavities in wood, or build mud nests. They take 

 no care of their young. The wasps which build the mud nests of many 

 cells, which are famiHar in most parts of this country, provision these 

 cells either with the caterpillars of butterflies or moths or with spiders. 



Another insect type which lives in societies and shows specialization 

 and polymorphism is the ant (Fig. 192). There are many species of 

 ants, and they form what has been recognized as a dominant type, 

 dominance being shown in the following ways: (1) by the vast number 

 of individuals which exist; (2) by the variety of structures they display, 

 there being a very large number of species; (3) by their wide distribu- 

 tion, which includes the entire globe; (4) by their longevity; and (5) 

 by their manifold relationships to plants and to other animals. Though 

 the males live only for several months, the lives of the workers may 

 cover a span of five or six years, and the queens may survive for as many 

 as fifteen years. Among ants 27 different types of individuals have been 

 recognized, including 7 types of males, an equal number of types of fertile 

 females, and 13 types of infertile females or workers. Not all of these 

 exist in the same society, but many of them may. Among the workers 

 are food gatherers, nurses, soldiers, and other types. This division of 

 labor is accompanied by great differences in size and structure, fitting 

 the different types of workers for the particular duties they have to 

 perform. 



