304 H. B. TANTHAM. 



sure that there is iilso chromatin present, sometimes perhaps 

 only loosely packed — at any rate in many cases (PI. 18, figs. 1, 

 2, and 4 show position of this). Further, Koch depicts 

 chromatin as occurring at the apex of P. bigeminum from 

 Africa (1, taf. 1, figs. 1 to 4), and Nuttall and Graham-Smith 

 figure masses of apical chromatin in P. can is (8, Diagram 1, 

 figs. 3, 4, 14, 20; Diagram 3, figs. 4, G, 8, 9, 13, IG, 19). 



In a Trypanosoma, carefully stained by the Romanowsky 

 method, as by Giemsa's solution, the nucleus appears bright 

 red and the blepharoplast violet-red in colour. In Piro- 

 p las ma, if the two lateral chromatin masses, more or less 

 unequal in size, be strictly homologous with the nucleus and 

 blepharoplast ' of a Trypanosome, one would expect similar 

 differences in staining reaction. In the specimens which have 

 come under my observation it is diflicult occasionally to dis- 

 tinguish in depth and colour of staining between the larger 

 and smaller chromatin masses of this minute parasite, as 

 sometimes the one, sometimes the other, may appear slightly 

 more deeply stained, and a difference in tint, as regards 

 violet, is exceedingly difficult to determine in this case. 

 However some specimens certainly showed the blepharoplast 

 more violet in tint after staining. Furthermore, Piroplasma 

 is generally intra-corpuscular, and relatively not often free in 

 mammalian blood, and is much smaller than any Trypanosome, 

 while the exact method of staining and mounting the prepara- 

 tion, together with its age, are of the utmost importance in 

 determining the finer staining reactions of chromatin. 



As regards the structure of the chromatin masses, it is very 

 difficult to make out any details in such small objects. The 

 principal nucleus and blepharoplast appear compact, and 

 separate granules of chromatin cannot be made out in them 

 with any degree of certainty, though, as a rule, the nucleus 



^ The term "blepharoplast," as relatiiiij to Piroplasma, is used in this 

 memoir lor coiiveuiciiec, and without prejudice (o its literal meaning as a 

 nuclear body related to a Uagellum. In tlie present state of our knowledge it 

 is impossible to state delinitely wliethcr a ll;igellate stage occurs in the life- 

 liistory of Piroplasma or iiol. (vide Seel . VJ). 



