66 SUMMARY OP CURRENT RESEARCHES RELATING TO 



sporoblast, and this is probably the stage at which it occurs in other 

 forms. This mode of reduction offers a simple explanation of the odd 

 chromosome number which is so common in Gregarines ; it is the 

 haploid number which is present in every nucleus in the whole life-cycle 

 except the zygote nucleus. 3. As Dobell has shown, it is futile to try 

 to interpret the Protozoa in terms of the Metazoan cell. *' Clarity of 

 thinking will not come in Protozoology until the Protozoa are fully 

 recognized as non-cellular organisms, comparable with whole Metazoan 

 individuals rather than with their single component cells." J. A. T. 



New Gregarines. — D. Kbilin {Parasitology, 1920, 12, 154-8, 1 pi.,. 

 2 figs.). Descriptions of Allantocystis dasyhelei g. et sp. n., from the 

 midgut of the larva of a Ceratopogonid {Dasyhelea obscura), and of 

 Dendrorhynchus systeni g. et sp. n., from the midgut of the larva of a 

 Dolichopodid fly, a species of Systenus. In the first the two sporont& 

 associated for reproduction do not change their form, but secrete a very 

 long sausage-like cyst. The only other Gregarine where the sporonts do 

 not contract before sporulation is Ceraiospora from a Polychast. In the 

 second genus the epimerite has the form of a disc surrounded by 

 numerous more or less ramified papillae, which are fixed in an epithehal 

 cell of the host's midgut. At various stages the cephalont, shedding off 

 the epimerite, can separate itself from the host's epithelial cell and 

 become a free moving sporont. Under the longitudinal striated epicyte 

 there is a network of very well-defined circular fibrils with oblique 

 anastomoses which surround the whole Gregarine. They correspond to- 

 myocyte fibrils. J. A. T. 



New Coccidian. — Paul Debaisieux {La Cellule, 1914, 29, 433-49, 

 1 pi.). A description" of Eimeria cystis-fellese sp. n. from the gall-bladder 

 of the Grass Snake {Tropidonotus natrix). The formation of micro- 

 gametes and of macrogametes, the schizogony and the sporogony are 

 described. The life-history conforms to that already established for the 

 genus. A comparison is made with the species Coccidium agamse from 

 an Agama and C. cerastis from a Horned Asp. The new species ha& 

 cysts with perfectly hyaline membrane, and the spores are spherical or 

 sub-spherical, both distinctive features. J. A. T. 



Life-history of Ceratomyxa acadiensis sp. n. — James W. Mavor 

 {Proc. Amer. Acad. Arts and Science, 1916, 51, 551-74, 3 pis., 3 figs.). 

 A new species of Ceratomyxa from the gall-bladder of Urophycis chuss^ 

 Zoarces angularis and Pseudopleuronectes americanus. The earliest stage 

 contains a single nucleus. By a heteropolar division this single nucleus 

 gives rise to a trophic and a propagative nucleus. The stage of the 

 myxosporidium with four nuclei probably arises by the division of the 

 trophic nucleus to form two tropho-nuclei, and the division of the 

 propagative nucleus to form two propagative nuclei. The origin of the 

 sporoblasts by the coming together of cells originally separate, as de- 

 scribed by Awerinzewifor C. drepanopsettse, is confirmed for C. acadiensis. 

 The presence of valve-cells and capsulogenous cells is noted. The two 

 germ-nuclei can be distinguished in the early stages of spore-formation 

 and until the spore is completely formed. J. A. T. 



