96 MCMURRICH. [VoL. XIV. 
that I saw, I could never find cases in which the daughter 
nuclei were completely formed, but still in contact with one 
another, awakened suspicion. The arrangement, too, of the 
nuclei in such definite, longitudinal, and transverse rows seemed 
hardly in harmony with the occurrence of such frequent ami- 
toses as the irregularities of the nuclei suggested; but, on the 
other hand, the occurrence of multinuclear cells seemed to be 
a point in confirmation of the occurrence of amitosis. In the 
land Isopods this condition is found rather infrequently, but it 
seems more common in marine forms. Thus cells with two 
nuclei are of rather frequent occurrence in /dotea robusta (Fig. 
6), and Carnoy states that in Czvolana nearly every cell con- 
tains from ten to thirty perfectly formed nuclei. Further 
consideration of this point led me again, however, to doubt the 
advisability of attaching much importance to it. In the land 
Isopods the cytoplasm over each nucleus is, as a rule, elevated 
more or less into a dome over which the chitinous membrane is 
folded; if, now, occasionally two cells unite to form a single 
dome, we would have apparently a cell with two nuclei, and it 
is possible that this may have been of frequent occurrence in 
Idotea, and that groups of cells have united together to form 
the supposed multinucleated cells of Czvolana. 
This explanation of the occurrence of the multinucleated cells 
is, I think, a possible and a plausible one. But let us consider 
on general grounds the probability of the occurrence of such 
extensive amitoses as the irregular form of the nuclei would 
lead us to expect, assuming that the irregularities indicate this 
phenomenon. We can imagine cell-division, amitotic or mitotic, 
taking place in the “ midgut,” either for growth or for regen- 
eration. To determine whether the growth of the “midgut” 
depended on cell-division or on the increase of size of the various 
cells, I made preparations of the gut of a series of specimens of 
Ontscus of different sizes, the largest specimen measuring 12.5 
mm. in length, and the smallest 4 mm. In each preparation I 
measured the length and breadth of a number of cells and took 
the average of the measurements; the results are represented 
in the following table: 
