150 BULLETIN OF THE 
projected far up among the contractile fibrilla. Tailed nuclei have 
been found by various observers, and sometimes the form has been 
attributed to mechanical injury in cutting. But this cannot be the case 
here, since they were plainest in sections 20 » thick at a level distinctly 
between the two surfaces of the section. From the general appearance 
of the sections I doubt the probability of the form being due to pres- 
sure in killing or preparing, and am inclined to regard their form as 
normal. Such nuclei have been explained as nervous; the only argu- 
ment which can be said to favor that view in this case is their position, 
and the absence of other known nervous terminations in the muscular 
layer. . 
The striated zone is narrow in the anterior chamber and at the pos- 
terior end of the body, but is elsewhere of nearly uniform width in any 
one specimen. It remains entirely colorless in carmine stains, but takes 
up hematoxylin with avidity and does not give it up in acid fluids, 
The protoplasmic portion of the muscular cell is highly granular and 
ordinarily does not stain at all. In the protoplasmic zone, however, there 
are cells which stain in eosin much deeper than the remaining elements 
(Fig. 29, x). The contents of these cells are so finely granular as to 
appear almost homogeneous. Lying in the body cavity near these cells 
are corpuscles, which in general appearance and affinity for stain are 
identical with them. It will appear probable, I think, from the figures 
given (Figs. 28-30), that these corpuscles are derived by abstriction 
from the deeply staining cells of the protoplasmic zone, They are 
found of all sizes, but never in very great numbers. There is some evi- 
dence to show that the deeply staining cells are the proximal ends 
of certain muscle cells, the contents of which are perhaps chemically 
altered ; the corpuscles, however, never contain nuclei, so far as I have 
seen. In view of the evident correlation between the thickness of 
the muscular wall of the body and the sexual maturity of the ani- 
mal, it is possible that the function of these corpuscles is nutritive. 
This will be discussed in connection with the description of the sexual 
organs. 
Evidence which goes to prove the formation of true cells from this 
layer is obtained from the study of the female in which the eggs were in the 
most immature condition of any which I had. Here (Plate IV. Fig. 59) 
sections show the body wall to be composed of the layers already de- 
scribed, except that the protoplasmic portion of the muscle cells is 
much shorter, and there seem to be proportionally fewer nuclei and 
fewer cells than in the sections previously described. In addition 
