NEMATODA 227 



bee is said not to increase in number there is an enormous growth in 

 size of the vagina which becomes prolapsed and forms eventually an 

 organ many times the size of the rest of the body, which remains 

 attached for some time but eventually disappears. The parasitized 

 humble bees, after passing the winter in their nests, tend to emerge 

 early. In the spring very often inactive bees may be caught which 

 prove, on dissection, to contain one or more of these enormous 

 sausage-shaped bodies, each of them full of eggs and larvae, which 

 escape through the gut wall and become free-living. 



Atractonema (Fig. 171 A), a parasite of the Cecidomyidae (p. 439), 

 has a similar life history. 



15-2 



