chap, xiii.] DEVELOPMENT OF GREGARINA. 



475 



lobster the following stages have, however, been 

 observed. 



The protoplasm, which has not been directly ob- 

 served escaping from the spore, is first seen as a small 

 amcebiform and apparently non-nucleated mass. 

 Passing into a quiescent condition, it becomes differ- 

 entiated into ectosarc and endosarc, and then gives rise 



Fig. 200. Figures of Gregarina of Earthworm. 



A, Separate form ; B, encystment completed ; c, formation of pseudonavicellae. 

 (After Stein and LieberkUun.) 



to two processes, one of which is stiff, and the other 

 actively motile ; in the latter granules are richly de- 

 veloped, and it is the first to become elongated and to 

 separate from the parent mass. It has now the form 

 and something of the movement of a thread-worm, 

 whence it has been called the pseudo - filaria ; 

 within this elongated mass a nucleolus and a nucleus 

 become apparent, the tube shortens, becomes divided 

 into protomerit and deutomerit, and, later on, deve- 

 lops a cuticle ; so that we have here a minute 

 example of the giant Gregarine. The stiff process has 

 meanwhile absorbed the remainder of the parent 



