EKPEODUCTION OF KALFIDOEHYNCHUS ARENiCOL.E. 573 
3’lie larger karyosomes all cousist of two layers — an outer 
dense layer which stains deeply and strongly with Heiden- 
hain’s hgeniatoxylin and other chromatin stains, and is, in fact, 
hasophile, and an inner part which has not so strong an 
attraction for basic stains, stains palely with Heidenhain, 
and strongly with acid stains such as orange G., Licht-Griin 
and picric acid, etc. The outer layer is, of com-se, chromatin, 
and the inner is nucleolar substance or plastin. The smaller 
karyosomes contain no plastin. They consist wholly of 
basophile chromatin. This, it seems to me, is only an 
expression of the fact that, as the karyosome increases in age 
and size, it becomes by degrees converted from a basophile 
into an acidopliile substance — i.e. from chromatin into 
plastin. The larger karyosomes are often divided up into 
a number of small chambers, each chamber being surrounded 
by a wall or walls of chromatin. In fig. 10 there is a karyo- 
some in which this process is beginning. This drawing 
shows the nucleus of a gainetocyte, but the nuclei of tropho- 
zoites often contain karyosomes in the same condition. 
There can be little doubt that the chromatin of the partitions 
and of the little knob-like thickenings is derived from the 
dense outer layer. 1’his turning in, so to speak, of the 
chromatin may take j)lace in order to increase its area of 
action, for the result is an increase in the quantity of the 
])lastin, and ultimately this increase is at the expense of the 
chromatin. 1 have seen karyosomes in Avhich there Avere 
larger chambers Avith thinner walls, and others from Avhich 
the outer rim of chromatin had gone completely. It seems 
as though finally the Avhole karyosome becomes converted 
into plastin. 
The karyosome divided up into chambers resembles on a 
small scale the karyosome of Aggregata as described by 
I\Iorott' (loots). 
Kei’KOduction or the Kauyosoiaies. 
Increase in the number of kaiyosomes takes place by a 
kind of internal budding from the chromatin layer. I have 
