ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 323 



is promised, discussing the meaning and homologies of these features. 

 A note is added upon another parasite of Periplaneta, which is probably 

 an undescribed Myxosporidian. 



Wall of Myxosporidian Spores.* — L. Leger and E. Hesse find that 

 the sporal wall is not a simple secretory product, but is always formed 

 from two parietal cells, each of which forms one of the valves of the 

 spore. 



New Microsporidian from Loach, t — Casimir Cepede describes a 

 rare cryptocystic Microsporidian — Plelstopliora macrospora sp. n. — found 

 once in Cobitis barbatula in Dauphiny. 



Reproduction of Monocystid Gregarines.J — L. Brasil describes the 

 changes which occur in the cyst of the species of Monocystis found in 

 the earthworm, and which lead to the formation of gametes. Three 

 kinds of mitosis appear to occur. What is perhaps more important, 

 there is a dimorphism of gametes produced from one cyst. The two 

 Gregarines which become apposed in conjugation, do not give rise to 

 absolutely similar gametes. There is a conjugation of the larger and 

 smaller gametes — a hitherto overlooked, slight, but real anisogamy. 



Eleutheroschizon duboscqi, a new Sporozoon.§ — L. Brasil describes 

 this new parasite, from the intestine of Scoloplos armiger at Luc sur 

 Mer. It occurs attached to the epithelium usually, but is sometimes free 

 in the gut. It is a relatively rare parasite, occurring in August and 

 September in one individual in twenty. The infected Annelids usually 

 contain many parasites : there are often nearly 100 in a section 10 /* in 

 thickness. The parasite is dome-shaped, 30 //. long, and carries a sharp 

 point, which is sometimes bent like a hook, upon the convexity. The 

 base bears a double set of lobes which penetrate into the epithelium. 

 There appears to be a long series of schizogonic multiplications ; the 

 merozoites are small and claviform. In its extra-cellular schizogony, 

 and extra-cellular growth of merozoites, and in the pari passu increase 

 in the number of nuclei, and the dimensions of the schizont, this new 

 form approaches the Schizogregarines, but nothing is yet known of the 

 conjugating stage. 



* Coniptes Rendus, cxlii. (1906) pp. 720-2 (8 figs.). 



t Tom. cit., pp. 56-8. 



t Arch. Zool. Exper., iv. (1905) pp. 69-99 (2 pis.). 



§ Arch. Zool. Exper., iv. (1906) Notes et Revue, pp. xvii.-xxii. (5 figs.). 



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