BY T. HARVEY JOHNSTON AND J. BURTON CLELAND. 



681 



C.Cff 



structure. A capsule could be distinguished surrounding most of 

 the forms. 



Still older hsemogregarines were present in the films. They 

 showed the presence of a short though distinct " tail " lying bent 

 round oil the concave side of the "body." The nucleus was large 

 and as a rule situated near the bend. These tailed forms reached 

 0-018 mm. in length (measuring along the midline and including 

 the tail). The surrounding capsule was usually recognisable. A 

 few very broad but relatively short capsulated forms (0-013 by 

 0-004 mm.) were also present. Here the nucleus was large, and 

 rounded. A fact worthy of mention is that the protoplasm of 

 these hfemogregarines frequently showed the presence of relatively 

 large chromatic granules staining a deep blue. These granules 

 were situated in the vicinity of the nucleus, being scattered 

 between it and the posterior end of the parasite as well as in the 

 immediate vicinity of the anterior border of the nucleus. In all 

 cases observed it was noticed that the other end of the organism 

 remained free from them. 



The infected cells were 

 usually longer and narrower 

 than normal, and the host- 

 nucleus was frequently dis- 

 placed, sometimes coming to 

 lie at the side of the corpuscle. 

 No cell was seen in which the 

 nucleus had been ejected. A 

 few cases of double infection 

 were observed. Some para- 

 sites were found lying free, 

 but very probably they had 

 been set free by the rupture Text-flsr. i. 



of the parasitised cell. One ^^- ' ^"^"'i?^' ^"^ of parasite-C, 



^ . capsule— C.GR., chromatic granules — 



very interesting parasite was H.N., host-nucleus— N., nucleus of 



seen in proce.ss of extrusion parasite. 



from its host-cell, probably as the result of artificial manijiulation. 

 The anterior half of the hsemogregarine (text-fig. 1) projected 

 53 



