82 PRACTICAL PARASITOLOGY 



Gregarines, these granules are so numerous as to render the organism 

 quite opaque, the nucleus showing only as a lighter spot In the small 

 varieties, on the other hand, the granular contents are frequently 

 so insignificant that the transparency of the protoplasm is unaffected 

 by them. In the latter case, however, the endoplasm is readily 

 distinguished from the hyaline ectoplasm by its coarsely-meshed 

 structure. The endoplasm is not homogeneous, the body of the 

 Gregarine being divided into two parts, placed one behind the other, 

 and this division is frequently apparent in the external structure. 

 The anterior portion, or protomerite, is considerably shorter than the 

 posterior portion, or deutomerite, which contains the bladder-shaped 

 nucleus. The two portions are separated by a divisional wall, 

 which cuts through the endoplasm and is formed entirely from the 

 superficial layer of the ectoplasm, with which it is continuous. 



Gregarines are frequently seen 

 joined together in pairs, the hinder 

 end of one being attached to the 

 anterior end of the other. More 

 rarely groups are formed, several 

 (two to three, very occasionally 

 four to five) small individuals be- 

 ing attached side by side to a 

 larger one. 



It is rarely possible to follow 

 PIG u.-Gregarini mmeri Schneid., directly the process of encystmen t. 



from the gut of a leaf-beetle (Chrysomela _ * i - , 



Portion of the surface. Cu. t Two Gregarines, which have be* 



, <=ome attached in the manner just 



from Brauj.) described, proceed to perform rota- 



tory spiral movements round one 



another, at the same time secreting a slimy envelope. As in the 

 monocysts, the two parent Gregarines are seen lying rolled up in the 

 young cyst. The young cysts inhabit the hinder end of the gut of the 

 mealworm and are not very frequently encountered, though when 

 found they are usually present in large numbers. 



The further development of the cysts takes place, not in the 

 intestine of the host, but in the open. The cysts should be isolated 

 under the microscope and put into a damp chamber. This procedure 

 complicates the technique, as moulds are very likely to form. Such 

 a contingency is only to be avoided by the exercise of scrupulous 

 cleanliness, the maintenance of control specimens, and the immediate 

 removal of commencing growths. The developmental phenomena 

 closely resemble those of the monocysts. A sex dimorphism in the 

 gamete stages of Gregarina has not been observed. The cysts of 

 this species differ, however, in possessing canal-like depressions in 



