88 
J. E. BLOOMFIELD. 
colour due to granules. In shape they would be flat plates of 
an oblong outline, were they not generally bent on themselves 
and curved in various places. Often they are very much elon- 
gated, the longitudinal dimensions exceeding the transverse four 
or five times. 
An interesting fact in regard to them is that they are com- 
posed of two distinct substances, one a hyaline transparent 
groundwork of a refractive index, very little differing from that of 
water, in which is held an irregular network of a denser substance 
with large granules, many of which, as shown by Klein for intra- 
nuclear granules, are the ends of rods of the network in optical 
section ; but this is not the case with all. In one part of the 
cell, varying in position, but in the corpuscles of an elongated 
shape, generally situated at one of the ends, is a nucleus : some- 
times two. Of these nuclei there is little indication in the fresh 
state except that at a certain spot the protoplasm is slightly more 
dense and opaque in appearance (figs. 51 — 59). Under 
treatment with osmic acid and picrocarmine the rods of the net- 
work split up into granules, often not quite completely, so that a 
moniliform outline is the result (figs. 60 — 65). 
Salt solution causes a slight shrinking of the network. 
The effect of water is instructive. When it has been added to 
a preparation in salt solution, the first effect is that the network 
loses its clearness, but continues to be visible for some little 
time. Then the corpuscle begins to swell until it becomes a 
hyaline sphere, containing granules which dance in rapid 
Brownian motion, and the nucleus is exposed to view. Dilute 
acetic acid has the same effect (fig. 66). 
Osmic acid, when applied in solution and picrocarmine, swell up 
the corpuscle in a similar way owing to their water, but when 
glycerine is applied (as is usual for preserving the preparation) it 
is reduced again in size. 
The vapour of osmic acid causes the network to disappear, 
leaving granules in its place. 
The proportionate amount of tliis network varies a good deal. 
In some corpuscles the meshes are large and distinct and the 
rods of large dimension, but in others the meshes are small and 
irregular, and often the rods very fine. 
At all times the arrangement of the network is hard to de- 
termine accurately, and it is only possible to give an idea of it 
in a drawing by diagrammatic treatment. 
Of the function of these corpuscles I can only, as I have said, 
make a guess. The stages in the development of the seminal 
reservoirs in which they are found are the following : in large 
well-developed reservoirs they are large and numerous, but 
in reservoirs taken from those large dark worms, which seem 
