NOTES ON SPOROZOA III. 
203 
cerued. In regard to the first point, the very fact that the 
organella seen in H . stepanovi is a nucleolus and not a 
karyosoine explains why it does not divide, as I hope to show 
below (cf. pp. 213 and 214). 
With regard to Eeichenow’s doubts about the occurrence 
of promitotic division and the presence of an intra-karyoso- 
inatic centrosome, I must say I think they are quite 
unfounded. lu the first place, both my own observations on 
the same Coccidian and those of Chagas on an allied form 
support Jollos^ account (loc. cit.) in so far as regards this 
detail. Further, I have found a precisely similar division of 
the karyosome by means of a centrodesmose in an early phase 
of the Haemogregarine, Karyolysus lacertm.^ And, as I 
have previously remarked, the presence of a centriole within 
the karyosome may be legitimately and reasonably assumed 
where the occurrence of a centrodesmose is noted. From a 
study of Trypanosomes, 1 know how difficult it often is to 
actually distinguish the centrosome, even in the large kaiyo- 
some of a relatively large individual, although the occurrence 
of a centrodesmose in the division of the karyosome (e. g. of 
the trophouucleus) has long been well known. Nevertheless, 
Minchin and 1, in our notes on 'J'. rairn (20), clearly demon- 
strated the actual presence of a centrosome in the resting 
karyosome. Moreover, as regards the Hmmogregarines, since 
Keichenow’s paper appeared, some interesting observations on 
the leucocytic parasite of the dog, Ilepatozoon (Ilaimogre- 
garina) canis, have been published by Wenyon (37). Here, 
too, a distinct promitotic division of the karyosome is figured; 
and iu the case of this parasite, the karyosome is relatively 
very small in some phases, when it probably represents little 
more than the centrosome itself. Even in the nucleus of 11. 
stepanovi, it is not impossible that a centriole is really 
also present, and it is just iu regard to this detail that 1 think 
the suggestion of Hartmann and Chagas (10) may apply, 
namely, that this minute granule may have escaped recog- 
nition owing to the difficulty of distinguishing it amid the 
* Cf. also footnote to p. 205. 
