150 
R. T. Young 
and that botli are nueleo-albuminous or chromatic in character. Coupled 
with my results above stated on the nuclei of Moniezia , they Support 
my previous contention (1. c., p. 236) that the so-ealled »nueleoli« are 
not true nueleoli, but rather the chromatin of the nucleus. 
A careful study of several nuclei convinces me that here also de- 
finite nuclear membranes are lacking. 
An examination of over 3000 x ) nuclei showed no mitotic figures 
with one possible doubtful exception. 
Taenia serrata. 
(Fig. 7.) 
I wish here to add a few observations to those alrcadv given in my 
previous paper (1. c.) on tliis form. In the section sliown I find distinctly 
differentiated regions of atvpical cells in the sub-cuticula. In some 
places in the worin from which tliis section was cut these regions pass 
gradually into those where typieal cells predominate, in other places 
the two are sharply marked off from each other. Scattered among the 
typieal cells are many atypical ones and vice versa. If these differences 
were due to differences in eontraction of different parts of the worin, 
one would expect to find evidence of such differences in the cnticula, 
muscles and parcnchyma. But such does not occur. All parts of the 
tissue except the sub-cuticula are precisely similar. Tlie only conclusion 
which I can draw from such evidence is that these staining differences 
are of physiologieal import. 
Anoplocephala sp. 
(Figs. 8, 9 and 10.) 
I find here in the sub-cuticula and parenchyma varving stages of 
nuclear developement. There are numerous masses of granulär cyto- 
plasm which contain no evidence of nuclear structure. This I have de- 
termined by careful foeussing, in those cases in which the mass is con- 
tained within the thiekness of a single section. Rarely one fine 1 s similar 
masses containing a primitive nuclear lnembrano, but without any clirom- 
atin content; some contain isolated »nueleoli«, while otliers again con- 
tain »nueleoli« surrounded by membranes of varving degrees of density, 
and otliers still an indefinite chromatic net-work with a distinct »nucle- 
x ) See footnote 1), p. 145. 
