250 ENTOMOLOGICAL NEWS. [October, 



genitalia ! Finally, the body of the worm falls, and the genitalia 

 continue to live an independent existence, nourished by osmosis 

 in the body-cavity of the bee. It is estimated that the genitalia 

 have hypertrophied 60,000 times their natural size, and have 

 become 15.000 to 20,000 times the size of the original female. 



In the meantime numerous embryos have developed within the 

 uterus; these embryos fall into the body-cavity of the bee and 

 become free, probably boring through the intestinal wall of the 

 host and being passed, or in some cases by the death and decay 

 of the bee. Upon becoming free, they develop their sexual or- 

 gans and copulate, the males die and the females await the oppor- 

 tunity of obtaining a Winter home in the next Winter's female' 

 humble-bees. 



It is almost needless to add that the presence of these parasites, 

 especially in large numbers, brings about an atrophy of some of 

 the organs, more particularly of the internal genitalia of the host, 

 and this causes the female bees to remain more or less sterile. 



The parasite described {Spherularia bombi) does not represent 

 the only species of nematode in which we find these gynecological 

 conditions. Leuckart has described a parasite (Atractonema 

 gibbosum) from the body-cavity of the larva and pupa of a small 

 Cecidomya which has a similar life-history, but in which the pro- 

 lapsus vagina? occurs to a more moderate degree. I have also 

 frequently noticed prolapsus vagina* in the genus Oxyuris (pin- 

 worms) more particularly in O. ambigua Rud., 1819, found in 

 rabbits (Lepiis cuniculus). This condition, which is not infre- 

 quently noticed in the worms found in the intestines, can be 

 brought about artificially by suddenly immersing the parasite in 

 cold water. 



EXPLANATION OF PLATE XI. 



Fig. i. -Normal young worm. 



" 2. Female with beginning evagination of the vagina. 

 " 3. The evaginated vagina has grown larger than the worm and con- 

 tains the other genital organs and the intestine. 

 4. Spherularia bombi as usually found. The body of the worm 



has fallen. 



" 5 Transverse section through fig. 4. 



Figs. 1-5 are taken from one of my old Leipzig sketch-books, and figs. 

 2, and 5 at least, and possibly also fig. 3 were made from 

 Leuckart's original preparations. 



Fig. 6.S. bombi with the body of the worm still attached. After I.ub- 

 bock, from Cobbold. 



All figures greatly enlarged. 



