No. 3.] BUDDING IN PEROPHORA. * AIZ 
the Figs. 77, 78, which he gives in support of his statement 
that he believes he has observed instances where this is taking 
place, are cases in point; it does not seem to me that there is 
any evidence that the cells marked 4.c' have come from the 
vesicle, as there is no connection between the two, and they 
might simply be outside cells lying in depressions of the wall. 
I have observed no cases in P. vzridis where I could be posi- 
tively sure that cells of the blood were derived in this way, but 
I regard it as extremely probable that at certain times or in 
certain buds at least such a process does occur, for it is difficult 
to imagine where these cells come from if not from the inner 
vesicle. If this be true, then the pericardium and dorsal tube 
in P. viridis are ultimately derived from the vesicle, and in 
P. annectens those cells which are directly given off into the 
rudiments of these structures and the blood cells which aid in 
their formation are cells of the same kind, having come in both 
cases from the wall of the vesicle of the same bud or a sister 
bud, 
I have recently had the opportunity of studying the bud 
development in another genus of the Clavelinidae, namely, 
Ecteinascidia, Herdman, and in this form I have observed 
undoubted instances where cells are passing out from the vesicle 
to be set free in the blood; they are simply budded off into the 
body space, and the appearance is quite different from that of 
Ritter’s Figs. 77, 78. A brief account of the development will 
shortly appear in the Axatomischer Anzeiger, but I may state 
here that I have found the dorsal tube, pericardium, and sexual 
organs to be all formed in large part by cells which are given 
off directly from the wall of the inner vesicle to their rudiments, 
but which are unquestionably supplemented by amoeboid cells 
from without. Here, therefore, the two processes do occur 
without a doubt, but, as all the cells which are concerned in the 
formation of these organs are derived from the same source — 
some, however, only indirectly—there is no essential difference 
between them. 
January 20, 1897. 
