TRYPANOSOMES IN 'IT'SETSE-FLIES AND OTHER DIPTERA, 255 
which at least shows that they regard both m and N as bodies 
of the nature of true nuclei. I hold that the terms centro- 
some and blepharoplast should not be applied to bodies which 
are recognised to be of the nature of nuclei; I differ, there- 
fore, from the Liverpool investigators, as from Keysselitz, 
mainly in a matter of the use of words. 
The memoir of Salvin-Moore and Breinl confirms me in the 
view I have expressed above; namely, that the body of a try- 
panosome contains two distinct nuclei, and that each of these 
two nuclei has a centrosomic corpuscle in connection with it ; 
for that, in connection with the trophonucleus, I use the term 
centrosome simply, since its function is mainly related to 
division of the nucleus; for that in connection with the 
kinetonucleus I use the term blepharoplast, since the flagellum 
takes origin from it. I can imagine that this type of struc- 
ture may be susceptible of variations and additions; the 
centrosome might be imbedded in a chromatic mass or true 
karyosome ; the blepharoplast might be lodged in the centre 
of the kinetonucleus; in either case the essential nature of 
blepharoplast and centrosome would not be affected. 
With reference to my diagram given above ('l'ext-fig. A, 
p. 174), I should explain that | have purposely given a negative 
picture, so to speak, of the nucleus and centrosome; that 
is to say, I have represented the centrosome as a distinct 
black granule in the midst of colourless chromatic granules 
making up the trophonucleus; had I represented the centro- 
some as it really is, namely, as a colourless granule in the 
midst of deeply staining chromatin-granules, it would have 
been as difficult to see in my drawing as it usually is in the 
actual preparations of trypanosomes. 
Salvin-Moore and Breinl deny any differentiation of try- 
panosomes in the blood; they state that the three types, 
slender, intermediate, and stout, distinguished by me, are 
“arbitrarily chosen examples in a continuous series of dimen- 
sions.” ‘To this I reply, first, that it has never been disputed 
that the different types are connected by transitions, since 
both the slender and stout forms are differentiations, more or 
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