92 



THE INVERTEBRATA 



Monocystis (Fig. 79). Without divisions of the body. Para- 

 sitic in seminal vesicles of earthworms. Several species, some iso- 

 gamous, others anisogamous. The spores escape either down the 



1 



Fig. 79. 

 Fig. 79. Monocystis. From Borradaile. Ay M. magna, x 2$. B, M. lumbnci, 

 X 85. The latter is covered with the tails of spermatozoa, the offspring of the 

 sperm mother-cell in which it was embedded. 



Fig. 80. Gregarina longa, from larva of Tipula, the Daddy-long-legs. Highly 

 magnified. After Leger. A, B, C, D, E, Stages of the development of G. longa 

 at first within and then pushing its way out of one of the cells of the intestine 

 of the Tipula larva. F, Mature form. c. cell of intestine of host ; nu. its nucleus ; 

 pst. parasite. 



vasa deferentia of the host or by the latter being eaten by a bird, 

 whose faeces contain them intact. Swallowed by another worm, their 

 cases are digested and the sporozoites traverse the intestinal wall to 



