94 MCMURRICH. [VoL. XIV. 
fact which recalls the ideas expressed by Korschelt ('g9), as to 
the influence of the nucleus in cell metabolism. These granules 
are not, however, always present even in specimens which seem 
to be fully grown, but when they are present at all they occur 
throughout the entire extent of the first and second portions of 
the “midgut.’’ It seems probable that the specimens in which 
they occur are older than those which, though approximately 
of the same size, lack them. 
The nucleus. —The nuclei of the “midgut” cells of the 
terrestrial Isopods have attracted considerable attention on 
account both of their large size and of the peculiar forms which 
they assume. Their most usual form is that of an oval, but 
this is rarely symmetrical (Fig. 1); very frequently the nuclei 
are lobate or provided with numerous blunt processes giving 
them the appearance of having been amceboid during life; and 
in some cases branched nuclei, resembling in shape those of the 
silk glands of the Lepidoptera, may be found, and others of 
most bizarre shapes are not uncommon. 
It will be unnecessary to figure the various forms which 
occur, since van Bambeke (’87) has shown many of them in his 
article on the artificial deformation of the nucleus. For these 
observations the intestine, taken from the living animal, was 
rapidly torn to pieces, and thereafter stained with an acid solu- 
tion of methyl green. After this treatment nuclei of remarkable 
shapes were frequently seen, and the conclusion was drawn 
that the irregularities were due to the mechanical injuries the 
nuclei had sustained. At the same time the author points out 
that sometimes, even when the treatment of the intestine has 
been most severe, no deformed nuclei can be observed; and v2ce 
versa, when care was taken to avoid injury of the tissue the 
deformed nuclei were sometimes abundant. I have not attempted 
to distort the nuclei in any of my preparations, but on the other 
hand have been as careful as possible to avoid injuring the 
tissue, and I find that in different specimens, treated as nearly 
as possible with the same care, sometimes nearly all the nuclei 
are extensively deformed, and at other times none of the more 
pronounced deformities can be observed (cf. Figs. 1, 3). I 
mention this fact in evidence of the supposition that many of 
