684 SUMMARY OF CURRENT RESEARCHES RELATING TO 



shapes of spicules, it is recognised that concerning factor (c) there exists 

 a sufficient number of facts to indicate that it is mainly to be relied on 

 in conjunction with factors (a) and {b) for our future comprehension 

 of spicule forms. Factor (a) in all its aspects is but a subsidiary one, 

 where complicated forms of spicules are concerned. Little can be said 

 regarding factor (&). 



Protozoa. 



New Sporozoon Genus from Nervous System of Cephalodiscus.* 

 W. G. Ridewood and H. B. Fantham describe Neurosporidmm ceplialo- 

 disci g. et sp. n., which occurs in the nervous layer of the ectoderm of 

 Cephalodiscus (idiothecid) nvjrescens Lank., a large form dredged by 

 the ' Discovery ' in the Antarctic Ocean. In this new genus the 

 trophozoite segments into uninucleate pansporoblasts, each of which 

 enlarges and becomes a spore morula. This gives rise to many small 

 spores, and a residual protoplasmic mass containing nuclei. The new 

 genus is placed in a new section (Polysporulea) of the Haplosporidia. 



Fresh-water Rhizopods.t— S. Awerinzew gives a systematic account 

 of the Rhizopoda Testacea, with a complete synonymy and Table for 

 species determination. To the systematic part, which also includes 

 descriptions of new species, is prefixed an account of the general morpho- 

 logy and physiology of fresh-water Rhizopods, which contains some new 

 points. Little importance is attached to the zones of the protoplasm ; 

 they depend on different chemical and physical conditions, and their 

 number and arrangement vary in the same species. The so-called 

 excretory granules consist of calcium phosphate. Rhumbler's phseosomes 

 are not transformed into the shell layers. Amongst the protoplasmic 

 inclusions are found masses of glycogen granules which are utilised 

 during reproduction. In the biophytic bacteria found in Pelomyxa, the 

 author sees food-stuffs simply ; they exhibit various stages of digestion. 



On the same ground the Zoochlorellte in the plasma of Rhizopods 

 are to be regarded as food materials ; the term symbiosis is not applicable. 

 There is a chapter on the reproduction of Rhizopods in which the life- 

 cycle of various forms is described. An interesting point regarding the 

 skeleton of the Rhizopoda Testacea is that on the whole it is larger in 

 the forms occurring within the polar circle than in those of temperate 

 zones. 



Life-cycle of Herpetomonas from Culex pipiens.| — W. S. Patton 

 supplies some interesting facts in the life-history of a Herpetomonas from 

 Cidex pipiens. There is a stage in the larva of the mosquito which is 

 very similar in form to the Leishmann-Donovan body, and which 

 multipKes in a similar manner. In the pupae, " rosettes " are formed and 

 in some cases flagellation has taken place. In the adult mosquitos the 

 parasites are elongated spindles with oval macro-nuclei and rod-shaped 



* Quart. Journ. Micr. Sci., li. (1907) pp. 81-100 (2 pis.). 



t Trav. Soc. Imp. Nat., St. Petersbourg, xxxvi. (1906) 259 pp., 5 pis. See also 

 Zool. Centralbl., xiv. (1907) pp. 60-2. 



% Brit. Med. Journ., 1907, pp. 78-80 (2 figs.). 



