7,qg FRANK E. BEDDARD, 



the central region of the body owing to the opacity caused by the 

 granules. On crushing au individual by pressing on the coverslip 

 these striatioDS were seen to extend on to the central region of the 

 body. 



Careful focussing showed that these striations were diie to the 

 presencG of fine ridges lying quite superficially; at the edges of the 

 body they could be seen to form a distinct layer outside the cuticle 

 though formed in all probability by local thickenings of it. 



It is quite common for Gregarines to exhibit a striatiuii of the 

 cuticle though the direction of the Striae seems to distinguish the pre- 

 sent species. In describing the encysted form I have callcd attention 

 to the fact that the cyst has the appearance of being composed of 

 innumerable closely felted fibres. In sections of the ,tair of the 

 encysted parasitc it was always possible to recognize (fig. 4) a layer 

 of specially thick fibres immediately overlying the structureless cuticle 

 of the Gregarine; it may be that these are the same as the Striae of 

 the unencysted parasite; but in this case it will obviously be necessary 

 to assume that the rest of the cyst is formed by the tissues of 

 the host. 



In any case it must be noted that the Constitution of the cyst in 

 this parasite differs as regards its relation to the cuticle of the un- 

 encysted form, from that of other Gregarines. 



There is some diflference of opinion as to the formation of the 

 cyst in other Gregarines. By some it is stated that the cyst is a 

 new formation altogether, by others that it is simply the persistent 

 cuticle of the free form. Bütschli (2) states that in the encysting 

 Clepsidrina hlattarum the cuticle of the free form disappeared. In 

 Adelea according to Schneider (6) the cuticular cyst is formed under- 

 neath the original cuticle and cannot therefore possibly be confounded 

 with it. 



Ruschhaupt however gives a rather diflferent description of the 

 formation of the cyst in Monocystis; it consists, according to him, 

 of two layers; the outer layer is the persistent cuticle of the free 

 stage, the inner layer is formed anew. 



In the present species it seems to me that, whatever 

 may be the origin of the portion of the cyst membrane 

 that contains nuclei, the delicate innercyst membrane 

 at least, if not also the layer of fibres outside it, is 

 the persistent cuticle of the free form. 



