238 WILSON. [Vot. II. 
of Manicina. And here it is at once seen that, contrary to 
Gotte’s idea, the invagination of the cesophagus does not 
necessitate the formation of endodermal sacs. In Figs. 5 
and 7 the cesophagus is already formed, but is still surrounded 
on all sides by endoderm. The apposition of the cesophagus to 
the surface ectoderm along the lines of the first and second 
mesenteries takes place later; and though, since this process 
occurs in the Scyphomedusz as well as the Zoantharia, it must 
date very far back. Iam inclined to believe it was secondarily 
acquired and was not a peculiarity of the primitive Anthozoa. 
This belief is supported by the entire absence of the process 
in the Alcyonaria (Wilson, 3). The explanation of the process 
is possibly connected with the early development of the first 
pair of filaments. 
BALTIMORE, March 25, 1888. 
