CONTRIBUTIONS TO THE ANATOMY OF KARTHWORMS. 461 
small cells, which seem to be just like the free corpuscles of 
the blood, suggests that they may be the seat of formation of 
the latter. 
On the other hand, the immense mass of cells contained in 
the anteriorly situated blood-glands is altogether out of pro- 
portion to the very scanty number of free corpuscles present 
in the blood. Moreover, Vedjovsky (39) has pointed out that 
certain valve-like structures, which are found along the prin- 
cipal vessels, are probably the source of the corpuscles, which 
would appear to be from Lankester’s investigations little more 
than the nuclei of such cells. 
I would not, however, venture to assert that this is not a 
function of the bodies in question. 
The close packing of the cells in the capillaries of the blood- 
gland, which seems occasionally (and perhaps only temporarily) 
to produce an actual occlusion of the lumen, and the general 
arrangement of the capillaries, would naturally tend to slow 
the circulation in this part of the vascular system; and it is 
also possible that the cellular mass which forms the greater 
part of the spherical dilatation along the ¢apillaries may play 
an active part in the elimination of waste matter from the blood, 
the waste matter being then temporarily stored up in the chlo- 
ragogen cells. Perhaps both these functions go on side by side. 
In any case I am inclined to compare these organs with the 
“pericardial glands”? of other Annelids and other Inver- 
tebrates. 
(2) Capsulogenous Glands. 
In three species of Pericheta, viz. P. Houlleti, 
P. aspergillum, and P. mirabilis, there are a number of 
small glands opening on to the exterior in the neighbourhood 
of the reproductive pores; the histological structure of these 
has not been investigated, and they have been, to a certain 
extent, confused with other structures, with which they do 
not appear to have anything in common. 
Perrier, in his description of Pericheta Houlleti, has 
stated that the spermathece (of which there are three pairs) 
