134 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



far the greater part of the cyst consists of an immense 

 number of spores. The endoplasm is the seat of spore- 

 formation. In the Microsporidia, this starts and pro- 

 ceeds either from one centre or from several. In the 

 latter case, each centre comprises (at first) a single 

 nucleus and a small portion of the cytoplasm in the 

 immediate neighbourhood, the whole becoming segre- 

 gated to form an " organella " of reproduction. Each 

 such centre is termed a pansporoblast. When, as in the 

 one family, including Thelohania, Pleistopliora, &c, there 

 is only one, it signifies that the whole individual becomes 

 a reproductive organella and commences to sub-divide up 

 into sporoblasts and spores (just as, for instance, a 

 Gregarine does). So that, in Phistophora, a ripe infec- 

 tion consists of a number of relatively small indi- 

 viduals, each being a single cluster of spores. This 

 fact, together with the blunter and thicker shape of the 

 spores in this genus, leads me to surmise that Linton's 

 sporocyst from the liver of Rhombus triacanihus (see above) 

 was probably a Pleistophora. 



To return to our Glugea specimen. The endoplasm 

 contains a great number of spore-forming organellse in 

 various stages of development, from little uninuclear ones 

 to large ones which are practically clumps of sporoblasts 

 (spbl.). The actual transition from sporoblast to spore 

 is extremely difficult to follow in the case of these minute 

 spores ; for a full account of the development in the large 

 forms, Thelohans paper should be consulted. I may 

 add, in passing, that anyone who desires complete informa- 

 tion on the group, cannot do better than read Minchin's 

 up-to-date and concise resume (5). Scattered about in 

 the endoplasm, and also occasionally met with in the 

 central mass, are large, sometimes drawn-out nuclei (n.) 

 with fragmented chromatin and a distinct nucleolus ( ?). 



