ON DEVELOPMENT OF ATYEPHtRA COMPEESSA. 397 
colouring fluid, and thus to bring out the nature of these 
spaces clearly, but unfortunately I have not succeeded in doing 
so. Still I think I have enough reason for believing that they 
are blood spaces, and nothing else ; for in the first place the 
sections of the heart and blood-vessels show us that in their 
cavities the same granular mass with similar cells occur. The 
granular substance and the cells exhibit no difference what- 
ever to those found in the ovary. In the second place, blood 
taken out of the body of the animal, and exposed to the fumes of 
osmic acid 05 per cent, strong for about five minutes, and coloured 
with Ranvier’s picro-carmine, shows the blood-corpuscles 
exactly corresponding in shape and size to those found in the 
ovary. In the third place, the above-mentioned cells are ex- 
tremely variable in form, and have no definite position in the 
granular mass. In the fourth place, the ovary of Panulirus 
japonic us, Gray, whose blood-vessels have been injected with 
a blue injecting mass, shows the presence of blood in similar 
places. Finally, fresh specimens show blood-corpuscles in the 
corresponding place. 
Blood not only gets into these spaces, but enters into the 
vitellogen, and fills up the spaces or lacunae between the adjoin- 
ing eggs (figs. 3 and 13 bs.), while in the germogen no trace of 
them can be detected. These blood spaces are best observed 
in the ovary not fully developed. 
Of the distribution of the blood vessels in the ovary, I have 
not been able to make a satisfactory observation in Atyephira ; 
but I have made it out clearly in Panulirus, of which I may 
therefore be allowed to write a few notes here. 
The ovary of Panulirus j aponicus, injected with the blue 
injecting mass, showed me that the sternal artery gives off a 
large branch to the right ovarian lobe. It soon divides into 
two branches, of which one, running anteriorly for a short 
time, sinks deep into the body of the ovary, while the other 
runs through the entire posterior lobe. Slightly anterior to 
the origin of the sternal artery, a small branch is given off to 
the left lobe directly from the lower side of the heart. This 
runs posteriorly for a short distance, but soon divides into two 
