So 



THE HUMBLE-BEE 



IV 



enormously in size, but also undergo structural 

 modifications favourable for the production of a 

 large number of embryos. In SpJucrularia bombi, 

 the remarkable parasite of the humble-bee, the 

 females, after copulating in the free state, migrate 

 into the queen-bees that live through the winter. 

 Here the gut degenerates and a kind of hernia of 

 the body-wall, containing the generative organs, is 



Fig. 16. Spharularia bombi. A, Female with partially protruded vagina, s. 

 B, The same with still more developed uterine growth, s. C, Uterine out- 

 growth fully formed containing ovary, oviduct, and uterus, w, The relatively 

 minute body of the worm. All magnified about ten times. (After Sedgwick). 



formed, while the body of the worm shrinks to a 

 small appendage. The eggs develop in the body of 

 the insect into larvae which pass out of the body, 

 become free and after some months become sexuallv 

 mature." l The parasite lives in the abdomen and 

 the uterine outgrowth, which may be found fully 

 developed in the hibernating queens where it attains 

 a length of about half-an-inch, looks at first sight as 



1 A Student's Text-Book of Zoolog)', by A. Sedgwick, F.R.S., vol. i. pages 

 282 and 283. See also R. Leuckart'.-. Neue Beitrage :. Kenntniss d. Nematoden, 

 Leipzig, 1887. 



