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II. M. WOODCOCK. 
karyosome (chi’omatin- nucleolus). If, as seems to me quite 
possible, a centrosome does occur in H. stepanovi, this is 
most likely to be in the centre of the chromatic network 
of tlie nucleus. 
Before concluding this section, I should like to add a few 
remarks about the nuclear condition seen in the piscine 
llmmogregarine, H. triglae, to make a comparison with which 
was my original intention in commencing to study the 
nucleus of K. lacertse. Minchin and Woodcock (loc. cit.) 
found that in both the small forms and the two large types 
of the parasite one or two large grains are frequently, though 
not invariably present, situated either close to the nucleus, or 
some varying distance from it; these bodies are very deeply 
stained and prominent in films stained by iron-hmmatoxylin. 
The nucleus itself appears comparatively pale and consists 
of small grains of chromatin, often somewhat faintly stained, 
on an irregular network. In Giemsa-stained smears it is 
difficult to distinguish this grain (or grains) when close to 
the nucleus. In our paper describing H.triglfe we regarded 
these elements as not chromatic, but rather of the nature of 
centrosomes. The extra-nuclear position of the body, together 
with the fact of its being often paired, seemed to us very 
much against its representing a karyosomatic element. 
Moreover, the appearance of these grains after being stained 
with Twort’s stain did not, in our opinion, furnish sufficient 
evidence in favour of their being chromatic. It is true that 
in freshly made preparations they were often stained red, i.e. 
with the neutral red, the chromatin staining constituent of 
Twort ; but they had no strong affinity for the I’ed, because 
in preparations which had been made some time the red tint 
had quite vanished from them, although the nucleus itself 
retained the red colour. I think we were misled by this 
behaviour after Twort. While it may be said that only 
chromatic elements are stained red by this stain, I think 
now that it is nevertheless quite likely that chromatin in 
some states or conditions may possess only very slight 
affinity for the neutral red. 
