The Somatic Nuclei of Certain Cestodes. 
143 
In order to test the Chemical nature of different cellular elements 
I employed the ordinary micro-chemical tests of artificial digestion with 
pepsin and trypsin, and treatment with 1% and 50% hydrochloric acid, 
1% potassium hydrate and 50% potassium cyanide, further reference 
to which tests will be made in the proper place 1 ). 
In most of my present material evidence of the de novo origin of 
nuclei is not as clear as I found it in Cysticercus pisiformis. I liave, 
however, found some additional evidence of this process, suggesting it 
to be of widespread occurrence in Cestodes. I have also found addition- 
al evidence supporting a belief in the primarily phvsiological rather 
than morphological character of the nucleus. I shall not in the present 
paper consider otlier than incidentally the sex cells of Cestodes, reserv- 
ing such consideration for a later paper, and confining my attention 
here to the somatic cells. 
Taeniidae. Moniezia planissima. 
(Figs. 1 and 2.) 
In the sub-cuticula of this worm may be found scattered masses 
of granulär protoplasm, which are similar to those which I have previouslv 
described in Taenia serrata and its larva. Some of these are several 
micra in dianreter, while others are ' smaller, but 3 or 4 micra in 
diameter. Careful examination shows some of them to lack any evidence 
of nuclei. Moreover they do not communicate (except indirectly thru 
the cvtoplasmic reticulum) with any nuclei -containing masses. A few 
of these masses, to which I have applied the term »cytogenic« in my pre- 
vious paper, contain very small »nucleoli« or nuclear granules entirelv 
isolated from any adjacent nuclei or nuclear matter; while in others 
still are very indefinitely outlined nuclear membranes, within which may, 
or may not be contained small, deeplv staining granules. These too 
are isolated from otlier nuclei and there is no evidence of their origin 
from pre-existent ones. The granules are usually surrounded by a lighter 
area. In some cases practically the entire cytogenic mass forms a nucleus 
as a delicate nuclear membrane may be seen forming around it, outside 
of which but few if any cvtoplasmic granules remain; while in others 
the entire mass is darkly stained, due, I believe, to thedepositionof nuclear 
matter thruout. 
x ) These tests were employed on Taenia crassicollis only. 
