188 ADAM SEDGWICK. 
coincide. Hence the protoplasm immediately around the 
nucleus appear more deeply stained than do the peripheral 
portions. 
6. A form closely resembling the above, except in the fact 
that the nuclear spongework is stained slightly, though not quite 
so deeply as, some of the extra-nuclear protoplasm (Pl. XII, 
fig. 2). There are only three (in the whole nucleus) small 
deeply-staining masses, which are not so conspicuous as in the 
first form, but are more deeply stained than the membrane and 
septa. 
Using the second of the two above-mentioned alternatives, 
we may state the difference between these two nuclei thus: in 
the first form the chromatin of the nucleus is aggregated into 
a number of small masses, while in the second form the chro- 
matin is, for the most part, diffused throughout the nuclear 
reticulum. The word chromatin being used to denote the 
property which enables the protoplasm to take up and retain 
the staining matter. The extra-nuclear protoplasmic threads 
possess this property, and may be said to possess chromatin, 
but it is in a diffused form, as in the second form of nucleus. 
c. In the third form (Pl. XII, fig. 3) the nucleus is divided 
by a number of septa, radiating from its centre, into chambers. 
The chambers are partially divided up into secondary chambers 
by prolongations of the septa. The septa are continuous 
externally with the extra-nuclear protoplasmic reticulum. It 
is impossible to speak of a distinct boundary of the nucleus in 
this form, and the substance of the nuclear septa and their 
prolongations is exactly similar in appearance and staining 
properties to the strands of the surrounding protoplasmic net- 
work or spongework. 
A number of chromatin masses occur in each chamber of 
this radiate nucleus—they appear to lie in the offshoots of the 
septa into the chambers and in delicate expansions of these. 
But it is impossible to determine exactly the relation of 
these chromatin globules to the protoplasmic network in the 
nucleus. 
This form of nucleus is most interesting, because were it not 
