1907.] A NEW HiEMOGREGARINE. 1101 



the nature of a shrivelled sheath pushed out by the parasite. I 

 could not, however, see any distinct line of separation between 

 what I regard as sheath and as body, and it may be that the 

 parasite, at the moment of leaving the corpuscle, has the anterior 

 end irregular in shape. I have tried to depict the object as I saw 

 it, and I must leave the matter there. The other example of this 

 stage which I found was too much obscured by neighbouring blood- 

 corpuscles to be made out clearly. 



To complete my study of these slides, I made some counts of 

 the different forms occurring in each. This was done with the 

 help of the mechanical stage, going methodically over a part of 

 the smear, so as to make sure that the same forms were not seen 

 twice, and counting all the forms met with. The following is the 

 result for slides A and B : — 



Young Full-grown 



intra- intra- Vermicules. 



corpuscular corpuscular / *■ .j 



forms forms Long Medium Stumpy 



(figs. 1-5). (figs. 6-8). (fig. 15). (fig. 11). (fig. 10). 



Slide A U 5 ... 93 



Slide B 24 28 60 10 11 



To these figures must be added the two parasites in the condition 

 of fig. 9, found on slide B. It is seen that on both slides the free 

 vermicules greatly preponderate, though this is less marked on 

 slide B than on slide A ; and the more detailed count made of 

 slide B shows that long forms of the vermicules are greatly in 

 excess of shorter forms. 



The other two slides, and D, show a very different state of 

 things. In the first place, free vermicules are comparatively rare, 

 and young forms, poor in chromatin, like those described above, 

 are not found at all. The majority of the parasites met with are 

 intra-corpuscular forms similar to that depicted in fig. 19, on 

 PI. LYI. The parasite has the form of an elongated sausage, slender 

 and drawn out, in very marked contrast to the stout forms already 

 described (compare figs. 6 and 7) ; the nonnal curve is concave on 

 the side towards the corpuscular nucleus. The cytoplasm of the 

 body is usually clear and free from coarse granulations. But the 

 most remarkable feature of the parasite is its nucleus, which forms 

 a band or zone at the middle of the body, equal in width to nearly 

 half the length of the body. The chromatin is arranged in the 

 form of ti'ansverse strands, which seem to wrap round the body 

 in this region ; between the strands of chromatin clear spaces are 

 seen, in some specimens abundantly, while in other cases the 

 texture may be closer and the structure more compact. The 

 strands of chromatin often appear to bulge beyond the contour of 

 the parasite, a point which Lt.-Ool. Wyville-Thomson has remarked 

 upon in his letter to me, and has depicted in the accompanyiiig 

 pencil-sketches. Nothing could be more different than the 

 appearance of the nucleus of the parasite in these two slides 



73* 



