212 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Chondrosia reniformis, not hitherto recorded from the Far East, Placortis 
simplex , hitherto known only from the Mediterranean, and Placinoloplia 
Bedoti g. et sp. n. 
Protozoa. 
Monograph on Coccidia.* — M. A. Labbe completes his systematic 
account of the various species of Coccidia, and gives a diagnostic key,, 
with a list of their hosts. The second part of the memoir is devoted to 
a discussion of the structure — the areolar cytoplasm, the reserve-gra- 
nules in the meshes, the nucleus, and the centrosome. In the next 
chapter the author describes the life-history of these parasites, (a) the 
penetration of the sporozoite into a cell ; ( b ) its transformation into a 
spherical Coccidium ; (c) the nutrition and growth of this phase ; and (d) 
its encystation and reproduction by internal division or by sporulation. 
In the sporulation there is a distinct chromatin reduction, comparable 
to the expulsion of a polar body. No conjugation has been observed, 
though its occurrence is suggested by the dimorphism of the spores in 
Pfeifferia. The last chapter discusses some general features of the life 
of Coccidia : — their habitat in Vertebrates rather than Invertebrates, their 
restriction to cpithelia, the manner of infection, the adaptation of parasite 
to host, individual and phylogenetic variations, relationship with Gre- 
garines, and so on. 
* Arch. Zool. Exper., iv. (1896) pp. 549-654 (7 pis., 19 figs.). 
