442 
in a complicated paraffin method, they may have collapsed. As I only 
found them in two individuals out of some hundreds of others, it is not 
probable that more will be readily obtained; but if one were carefully 
examined under a dissecting microscope, and the contents of the ducts 
stained for spermatozoa, it would easy to decide the matter. Frozen 
or celloidin sections could also be made. The funetion of the seminal 
ducts would obviously be that of receiving the contents of the seminal 
vesicles from the orifices of the vasa deferentia in the 15th segment 
(which would in that case not open on. to the exterior, but under the 
cuticle), and of conveying them to the clitellum. The connection be- 
tween the ducts and the tubercula,pubertatis; whilst it seems to 
imply that the spermathecal orifices would be placed 
against the centre ofthe.clitellum, and not, as now sup- 
posed, atthe anteriorend ofit, may also serve to give us a clue 
to the function of the latter, This may be either that of aggregating the 
sperms into spermatophores — thus assigning to the spermathecae a 
storing function only — or that of »cementing« the ducts to the orifices 
of the spermathecae, in order to prevent a waste of seminal fluid. 
Both these conjectures, however, are improbable, and the tubercula 
pubertatis must for the present remain a puzzle. For the rest, we can 
understand that, with the seminal ducts, the exchange of seminal fluid 
could be simultaneous — which is what probably happens. 
With the spermathecae full of spermatophores , it now becomes: a 
question of fertilization and of the cocoon.. The remainder of Vogt and 
Yung’s description, which deals with this, is open to the gravest. ob- 
jections. The alors cannot mean that the cocoon is formed immedia- 
tely after copulation, as that would, not only involve the greatest difficul- 
ties, but would contradict matters of very common observation; nor is 
there less difficulty in understanding them to imply that it is elaborated 
at a totally distinct union (reunis), taking place some little. or greater 
time after. For how could the contents of almost microscopic bodies 
traverse from the 14th segment to at least the 32nd, down rough chan- 
nels and without ciliary action.. It is easy to understand the steady 
accumulation of the male element.in the seminal vesicles, because a 
flow. must be necessary in order that any of it should reach the clitel- 
lum. But we have no such development in connection with the ova- 
ries, excepting of course the very small receptacula ovorum, and hence 
the difficulty. Further, let us suppose that the worms A and B in the 
fig. have just copulated, i.e. that an exchange of. sperms has been 
effected. Now the only, thing necessary in the case of each’, is that 
their eggs should be fertilised by the sperms already received. Vogt 
and Yung can see no other method of doing this than that of calling 
