68 The American Naturalist. (January, 
A study of sections of the intestine show that almost every cell, and — : 
especially those in the anterior region of the alimentary canal, is trav- : 
ersed by bundles of very strong fibres, which run from the luminal to 
the coelomic side of the cell, and inclose the nucleus as in a bard i 
cage, Fig. 4. These fibres when cut across curl slightly at the ends, — 
showing that they are elastic; and it is possible that they may, under 
certain circumstances, contract, thus forcing the nucleus out through 4 
the bars. The presence of these fibres certainly explains the re 
and branched, or even broken appearance, which the nuclei ohne 
present. : 
Experiment, however, demonstrates the fact that the principal, if not 
the only cause of these distorted nuclear forms, is merely the mecha : 
ical pressure incident to the ordinary methods of removing the intestine — 7 
from the body. I find that by pulling off the head segment and then l 
carefully separating the tail segment from the next anterior one the 
intestine can be slipped out of the body, generally without injury, $ simply a 
by pulling on the tail segment. I have prepared many such specimens n 
which do not show a single distorted nuclear form. If now an intestine — 
so removed be gently pressed in several spots with a blunted pencil, the 
distorted nuclei are found, after staining and mounting, to be locate 
immediately around these spots. If the entire alimentary tract ? 
gently pressed with a spatula, every nucleus may be caused to take t 
form, I believe, therefore, that these distorted nuclei are largely. 
not entirely, the result of mechanical pressure produced by contact 
with foreign objects. Whether cells which have undergone such pre 
sure may afterwards restore their nuclei to a normal condition, oF 
gain them, if altogether lost, is a question which I am now investigating: 
In some cases in which the intestine was removed with the mot 
pains-taking care a few cells were found in which a normal looking 
nucleus extending into two cells, Fig. 8. Some of these cases, I 
convinced, are amitotic divisions of the nucleus; e. g. figures 7 an 
show cells which are indented on the ccelomic side and in which t 
nuclei are dumb-bell shaped. That this is nota case of “ conjugation 
is evidenced not only by the shape of the cells but also by their size!" 
they are scarcely any larger than single neighboring cells. 
other hand there are many cases in which nuclear forms which mig 
be mistaken for amitotic division figures are plainly proclaimed to 
squeezed nuclei by the absence of a nuclear membrane from one €P 
Fig. 3 3 
There remains to be described the remarkable structure of some 
which, I believe, are entirely normal. In the anterior region 
