No. 3.] BUDDING IN PEROPHORA. 375 
organs, some of which have by this time begun to make their 
appearance, I wish to say a word about the partition of the 
stolon. 
As the inner vesicle of the bud is formed entirely from this 
structure, it is a matter of importance to know from what it is 
derived in the larva. It has never been observed in Perophora 
how the stolonic partition arises, although it is usually supposed 
to be of endodermal origin from its likeness to the similar struc- 
ture in Clavelina. Van Beneden and Julin (33) have shown 
that in the larva of Clavelina it is formed as a direct continua- 
tion of the epicardium, which arises as a diverticulum from the 
posterior wall of the branchial sac, and is, therefore, entirely 
endodermal. During the month of August, 1895, I made an 
attempt to discover the origin of the stolon in Perophora. 
Larvae were put into aquaria, through which water was kept 
constantly flowing, and, although they settled down and under- 
went the metamorphosis, at the expiration of nearly four 
weeks not the trace of a stolon sprouted from them. When 
larvae and young embryozodids were afterwards sectioned and 
studied, nothing like an epicardium, such as occurs in Clave- 
lina, was found. I am unable, therefore, to throw any light 
on the origin of the stolonic partition in Perophora, but it is 
fairly safe to say that it does not arise in the same way as it 
does in Clavelina. 
The Further Development of the Bud. 
At the time when the bud-rudiment begins to elongate, 
or very shortly after, the rudiments of several new structures 
are laid down. These are (1) the pericardium, (2) the pert- 
branchial sacs, (3) the dorsal tube, (4) the gut, and (5) the 
ganglion. They do not all arise simultaneously, and, although 
the rudiment of the pericardium is the earliest to appear, it 
will be necessary to describe the formation of the peribranchial 
sacs first in order to render intelligible certain relations between 
these and other structures. 
