500 FRANK E. BEDDARD. 
of structure from the cocoons of Lumbricus and Allolobo- 
phora. 
Neither do the cocoons of Acanthodrilus multiporus. 
It seems clear, therefore, that the formation of this structure 
is pretty much the same in all these genera, and that the 
various glandular structures—such as the atria, with which 
Acanthodrilus is furnished and Lumbricus is not—have 
nothing to do with the manufacturing of the cocoon. No 
doubt the clitellum alone is concerned in its production. 
The cocoons have a length of about half an inch. They 
are regularly oval in form, and have a slight stalk-like pro- 
jection at either end, such as occurs in Lumbricus. 
The colour is yellowish brown ; the empty cases have a clear 
transparent brown colour. 
The cocoon is formed of two perfectly distinct membranes 
which are readily separable after it has been cut open. 
Vejdovsky has remarked that this is the case also with Lum- 
bricus, particularly L. rubellus, where the outer layer 
forms a remarkable projection longer than the cocoon, and to 
which particles of soil adhere. 
The cocoons vary somewhat in size. In a cocoon from 
which the worm has escaped, a circular orifice at one end 
marks the place at which the young worm made its exit. 
The cocoon never contained more than a single embryo; 
even in the youngest stages which I examined (fig. 20a) there 
was but one embryo. As I opened about fifty cocoons, I feel 
justified in considering that this species may be characterised 
by the fact that. the cocoon only contains a single embryo; it 
is probable that there are a number of eggs originally enclosed 
in each capsule, but it is evident that they must disappear 
early. 
Among the Lumbricide one to three embryos seem to be 
the rule; but in Allolobophora fetida there may be as 
many as six. I found two embryos in a cocoon of Megas- 
colex ceruleus (8). 
In fig. 20 are represented the sizes of the embryos of the 
various stages which I examined ; the youngest is of course a, 
