ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 547 



-given particular attention to the gregariniform stage which occurs in 

 the course of the endogenous or asexual multiplication. It has been 

 vaguely called the amoeboid phase, but gregariniform is more accurate. 

 It is the truly active phase during which the parasite develops at the 

 expense of the blood-corpuscle. It recalls, on the one hand, the forms 

 of Hsemogregarina in the blood of Amphibians and Peptiles, and on 

 the other hand, the true Gregarines of Arthropods. 



Gametes of Stylorhynchus.* — Louis Leger describes the structure, 

 movements, and conjugation of the gametes of several species of Stijlo- 

 rhynchus. Each is a naked cell, with a granular cytoplasm, a circular 

 nucleus at one end, a flagellum at the other. The flagellum is con- 

 tinued as an axial filament to a little corpuscle immediately below the 

 nucleus. This may be compared to a basilar body, but it seems to the 

 author more like the centrosome of a typical spermatozoon. 



Chitonicium simplex.! — Prof. Ludwig H. Plate describes in more 

 detail and figures the cell-parasite which he has previously noted as 

 occurring in the mantle-chamber of Ischnochiton imitator. The young 

 parasite is intracellular, and has a very indistinct cell-membrane ; the 

 older free forms are rounded, with a distinct nucleus and well-defined 

 membrane. Multiplication takes place, either within or outside the cell, 

 by simple division. No trace of a sexual process could be observed. 

 The systematic position of the parasites is uncertain, but the absence of 

 chlorophyll or of cellulose suggests that they are not of plant nature. 

 They produce considerable injury to the epithelium of the host, result- 

 ing often in extensive sloughing of the cells. 



* Comptes Rendus, cxxxii. (1901) pp. 1431-3 (4 figs.). 

 t Zool. Jahrb., Supp. v. vol. ii. (1901) pp. 601-6 (1 pi.). 



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