55 



Characteristic is their prodigious procreativeness, their 

 profuse multiplication by sporulation, i.e., by fragmentation 

 of the body into numerous minute nucleated reproductive 

 germs or spores. These spores may serve for further in- 

 crease within a host or for infecting fresh hosts, thus en- 

 suring the spread of the species. The spores are either 

 grouped within tough-walled cysts, or separate and each 

 provided with a tough resistent coat. While many of 

 the Sporozoa are little more than inconveniences, others 

 produce disease often fatal in result. The Haemosporidia 

 are the cause of malaria in Man. 



ORDER GREGARINIDA. 

 Structure and Life History of Monocystis. 



Where is Monocystis magnet found ? 



In the reproductive organs of the Earthworm ( Lumbricus), 

 either free in the seminal vesicles or attached to the in- 

 ternal funnel openings of the vasa deferentia. 



Describe the Appearance and Structure of Monocystis magna. 



It is worm-like, a quarter of an inch long more or less, 

 .and its body consists of a clear thin outer cortex or ecto- 

 plasm and an inner medulla or endoplasm, finely granular, 

 in which there is a conspicuous oval and fluid nucleus. 

 This description is that of the trophozoite stage of the 

 parasite. 



Where is the Trophozoite of Monocystis agilis, found ? 

 Does it differ in any way when compared with the 

 Trophozoite of Monocystis magna ? 



In the fluid contents of the seminal vesicles of the Earth- 

 worm. It is of minute bize and oval shape (varying, how- 

 ever, when contracted during " euglenoid " movement). 

 The body structure is similar to that of Monocystis magna. 



