C. M. Wenyon 
305 
that they represent a higher developmental condition than the ordinary 
forms. I rather think that these are forms endowed with greater 
powers of resistance and to them may be due the fact noted by Row 
that the parasites of the sore are able to survive a longer time in the 
scrapings from the sores than do the parasites of Kala azar in the 
material obtained by splenic puncture. 
In these pointed forms the kinetonucleus is almost invariably 
between the nucleus and the blunt extremity, so that the tapering of 
the body is not a step in the direction of flagellum formation as one is 
inclined to suppose. These elongated forms, so aptly described by 
Dr Row as torpedo or cigar-shaped parasites, often occur in great 
numbers in the juice from the sore, and every transition between the 
typical oval body and the elongated narrow forms can be found. 
Amongst these may be seen some that have completely lost their 
chromatin, and appear in the film as homogeneous pinkish bodies of 
varying shape. Others occur in which the nucleus is lost while the 
kinetonucleus remains (PI. XII, figs. 27 and 28). Such forms are 
undoubtedly degenerate or involution forms. The elongated forms 
reproduce by division as do the more typical ones. It will be seen that 
the appearance in a smear from a sore differ in many ways from smears 
of internal organs in Kala azar. In this latter disease there is a much 
greater uniformity in the structure and form of the parasites, and one 
does not encounter the curious elongated and involution forms. The 
intracellular pai’asites, the typical oval bodies, in the two cases are 
indistinguishable, but the appearances in the sore smear differ very 
markedly in the deviation of the parasite from this type. 
The typical parasite (PI. XII, figs. 25 and 26) as is well known, is an 
oval or bean-shaped bod}^ with the deeply staining rod-shaped kineto¬ 
nucleus and the more brightly staining nucleus usually applied to one 
side of the parasite. The rhizoplast, first described by Mesnil, Nicolle 
and Remlinger in the parasite of Oriental sore in the same year that 
Christophers noted it in the parasite of Kala azar, is present in most 
cases. In well stained films it may be detected in almost all the 
parasites outside the cells, whether they are of the typical oval shape 
or elongated (PI. XII, figs. 22-26). It is not easily detected in the 
intracellular forms probably because of the obscuring effect of the 
protoplasm of the cell. It may thus be said to be a typical feature of 
the parasite. In the dried films stained with Giemsa’s stain, its con¬ 
nection with the kinetonucleus' can be made out. The kinetonucleus 
stains very deeply except on one side where there is a paler staining 
20—2 
