32 H. M. WOODCOCK. 



Expulsion of karyosomatic material into the 

 nucleoplasm. — Some of tlie smaller vacuoles probably run 

 together and unite to form larger ones^ for one often gets two 

 or three large ones — sometimes one very huge one — and a 

 number of little ones besides (fig. 33, h and c). Fig. 34 is a 

 section of the nucleus seen in Fig. 33 c (the Gregarine con- 

 taining it having been unmounted and cut^), and it shows an 

 occurrence by no means infrequent. In the karj-osome lies a 

 huge vacuole, which is obviously just ready to have its con- 

 tents expelled into the surrounding nucleoplasm, either by 

 diffusion through or by the actual rupture of the denser, 

 more deeply staining, portion, which is here very thin near 

 the surface. (I should add that, in some instances, the edge 

 or border of the karyosome stains deeper, and appears as a 

 thin, dark line, perhaps constituting a definite wall.) I 

 certainly consider there is an actual discharge, in some such 

 manner, of the contents of these huge vacuoles, for in the 

 karyosomes of ripe trophozoites about to commence sporula- 

 tion the vacuolisatiou is much more uniform. Fig. 36 shows 

 the nucleus of an encysted C, minchinii (a full-grown 

 sporont attached to the muscle), and the vacuoles in the 

 karyosome are all comparatively small and of about equal size. 



A similar elimination of karyosomatic material, though by 

 a rather different process, is described by Cuenot (loc. cit.) 

 in the nucleus of Diplocystis. The karyosome there buds 

 off little portions of itself, each containing a vacuole, into the 

 surrounding nucleoplasm," where they become eventually 

 dissolved. In Cystobia, on the other hand, the karyosome 



' The nucleus is somewhat flattened, owing to the original preparation 

 liaving been compressed by the cover-slip, and the nuclear contents are all at 

 one side, around the karyosome ; the karyosome itself is, however, perfectly 

 normal. 



- Tiie same process, in one form or another, is of frequent occurrence 

 outside Gregarines. In a Coccidian of the cuttle-fisli, E u cocci d iu m e berth i, 

 Siedlecki (37) describes a budding of the karyosome prior to the formation of 

 the gametes. As many as twenty secondary or dauglitcr-karyosomes are thus 

 set free, many of which at length dissolve in the nuclear-sap. An analogous 

 budding of the " nucleoli " of eggs also often takes place. 



