80 THE HUMBLE-BEE IV 
enormously in size, but also undergo structural 
modifications favourable for the production of a 
large number of embryos. In Spherularia boméi, 
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 

Fic. 16.—Spherularia 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 sexually 
mature.” ! 
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 4 Student's Text-Book of Zoology, by A. Sedgwick, F.R.S., vol. i. pages 
282 and 283. Seealso R. Leuckart’s ewe Bettrage z. Kenniniss d. Nematoden, 
Leipzig, 1887. 
