THE CYSTIC ENTOZOA. 483 



generation. The young cells, after acting for a time as the 

 organs of nutrition, become free and independent animals after 

 having thrown off young cells internally, which in their turn 

 act as organs of nutrition to their parent until they are fit to 

 become independent animals themselves. The particulars 

 relative to the peculiar mode of development of ths aniimal 

 will be adverted to more at length when we come to treat of 

 that function in Diskostorna ; in the meantime a few remarks 

 on the external character of the animal may be useful. 



It was of a greenish yellow colour when taken from its 

 habitat, and varied in size from a millet seed to that of a 

 middle-sized orange. The smaller specimens were all spheri- 

 cal, and very much corrugated ; the larger were quite smooth 

 and botryoidal the first of which appearances arose apparently 

 from the distension caused by the young ; the second, from 

 the young within it increasing irregularly in size. When a 

 section was made of an adult specimen, the interior was found 

 to consist of an immense number of young in various stages 

 of advancement, and all of them apparently having their 

 origin from the inclosing sac, either immediately or mediately. 

 Along with these the interstices contained a great quantity of 

 gelatinous matter, which appeared to be the assimilated food, 

 analogous to the pabulum of the seminal cells already spoken 

 of in another paper. 



III. OF DISKOSTOMA.* (PLATE XI.) 



Diskostoma acephalocystis is another animal belonging to 

 the Cystic Entozoa, and very similar in many respects to the 

 preceding genera ; it is, however, more complicated in its 

 structure than either. 



Diskostorna was met with in great numbers in the peri- 

 toneal cavity of a middle-aged man. About six or eight 



* Transactions of the Royal Society, Edinburgh, vol. xv., p. 564. 



