242 Proceedinys of the Royal Physical Society. 



along the body; these striations are very conspicuous in 

 individuals stained with polychrome methylene blue or 

 thionin, but are less clear in Giemsa preparations. Division 

 and further stages of the life-history have not as yet been 

 observed. 



I hope in a future publication to describe in fuller detail 

 both this and the following forms. 



4. Hsemogregarine from blood of P. flesus and 

 P. platessa. 



This parasite is a small creature, measuring 7 /* to 

 12 /A in length. There is a large nucleus, of much the 

 same type as that described for the form in the python, 

 only the karyosome is a more compact body, and does 

 not appear ring-shaped in the ordinary resting stage: it is 

 a more variable organ, and the appearance it presents in 

 the different specimens suggests that it is an important 

 element in the nuclear apparatus (Fig. 14). The number of 

 chromosomes is not quite easy to make out, but there appear 

 to be eight. The nuclear membrane is not at all a constant 

 structure. It is present in some stages, but very frequently 

 the chromatin lies arranged in definite little masses without 

 the faintest sign of a surrounding membrane (Fig. 16). A 

 very constant feature in this form is the presence of an 

 eosinophile body, lying towards the slightly more pointed 

 end of the creature. This body was at first taken to be 

 a vacuole, as it is absolutely unstained by methylene blue. 

 In all Giemsa preparations it stains a clear rose-pink, and 

 appears to correspond to a similar body found by Dr Kogers 

 in the Herpetomonas} which causes the disease known as 

 kala-azar. A centrosome is not present as a constant struc- 

 ture in the majority of specimens, but a well-marked granule, 

 whose appearance and staining reaction strongly suggest a 

 centrosome, is to be seen in a number of cases (Figs. 13, 14). 

 This granule appears to divide, and in certain cases marked 



1 The author uses the word Hepatomonas, but no doubt intends Herpe- 

 totnonas. 



