176 ADAM SEDGWIOK. 
staining more deeply than the rest of the reticulum—a pro- 
perty which is only visible in sections through the ovum—is 
probably merely apparent and due to the fact of their greater 
mass. 
There is then no yolk material in the ovum, unless these 
bodies and the small highly refractile globules which are 
present in very small numbers are to be regarded as such. 
The sponge-like structure of the ovum of P. capensis is very 
conspicuous. The meshes of the spongework must be occupied 
in life by a structureless fluid, for they contain in preserved 
specimens nothing presenting any structure, excepting the 
small number of globules and granules already mentioned. It 
can hardly be doubted, when the large size of the egg is con- 
sidered, that some not very remote ancestors of the Cape 
species must have possessed an ovum, heavily charged with 
food yolk. We may further conclude from what we know of 
the relationship of the food yolk to the protoplasmic reticulum 
in other eggs, that this yolk must have been contained in the 
meshes of the reticulum, which now contain only fluid. This 
view is strongly confirmed by the fact that in a species of 
Peripatus, living at the present day and closely resembling 
Capensis, viz. P. nove zealandia, the ovum is considerably 
larger than that of Capensis (1°5 x 1 mm.), and contains a 
large amount of food yolk. Our knowledge of the structure 
and early development of the ovum of this species is very 
small. It has been described by Hutton (6) and Kennel (8), 
and I have cursorily examined ova removed from hardened 
specimens. But the latter were too ill preserved to enable me 
to arrive at any satisfactory conclusions as to their structure 
and early development. ‘There can, however, be no doubt on 
the following points :—(1) They are very large, (2) they have a 
thick chitinous shell, and (3) they are very heavily charged 
with food yolk. The shell of the Cape species, is as already 
stated, a somewhat delicate, transparent, structureless, but 
dense membrane, and within it, and much more closely applied 
to the ovum, there is a second, apparently similar, but more 
delicate membrane. 
