THE CHROMATIN MASSES OF PIROPLASMA BIGEMINUM. 317 



V. Note on the Cytoplasm of P. bigeminum. 



As judged by the distribution of the stain, tlie cytoplasm is 

 more especially peripheral, and often a clear area is seen in 

 the centre. Such a clear area may be regarded as a vacuole, 

 though one must beware of such appearances, sometimes 

 deceptive, when observations are confined to stained prepara- 

 tions. However, vacuoles have been described in Piroplas- 

 mata by various observers while examining the parasites in 

 the living condition. The vacuolated condition, as determined 

 from stained specimens, is Avell shown in text-figs. 1, 2, 3, 9, 

 12, 21, 26, 27, and 32. A vacuole with a sharp and definite 

 edge is shown in text-fig. 33. It does not always follow that 

 the clear space inside a parasite, as diagrammatically repre- 

 sented in the text-figures, is a vacuole, for when one examines 

 the preparation under monochromatic light a slight shadow 

 may sometimes appear therein, suggesting a continuous cyto- 

 plasm within such parasites, Avhich may be more clear and 

 hyaline in the centre, or less permeable to stain than that at 

 the periphery. The vacuoles, of which more than one may 

 occur in a parasite, usually lie between the chromatin masses, 

 and appear only in the larger pai-asites. Two vacuoles may 

 occur in a parasite separated by a marked cytoplasmic 

 strand (text-figs. 3 part, 21 part, 22 part). 



The cytoplasm shows a granular structure, more especially 

 at the apical end of some forms (text-figs. 3, 12 part). The 

 very finely-granular character of the protoplasm is difiicult to 

 represent in drawings. The very small dots in the text- 

 figures, which figures are semi-diagrammatic, only show the 

 limit of the obviously stained area, yet that is almost the limit 

 of certainty in such small and delicate (endocorpuscular) 

 objects as Piroplasmata. 



The central clear area seen in most rounded parasites 

 would appear to be a vacuole. 



I was not able to obtain any further evidence as to the 

 character of the cytoplasm from an extended examination of 

 the stained free forms. 



