Note on the Presence of a Neurenteric Canal 
in Rana. 
By 
Herbert E, Durham, 
King’s College, Cambridge. 
With Plate XXVII. 
In the supplement number of this Journal (1885) Mr. W. B. 
Spencer says that he has found that the only communication 
which exists between the neural and alimentary canals in 
embryos of Rana is by means of the blastopore, and he there- 
fore doubts whether, strictly speaking, a neurenteric canal is 
present in Rana. 
In the long vacation I cut some longitudinal and transverse 
sections of embryos of Rana, and on examining them I found 
that there was a well-marked communication between the 
alimentary tract and the neural canal without the intervention 
of the blastopore. Upon this I set to work to confirm this 
result by cutting a large number of embryos into series of 
sections, both longitudinal and transverse. As the number of 
my own specimens was rather limited, Mr. Sedgwick kindly 
allowed me to choose any suitable embryos from the labora- 
tory materials. i 
In all the embryos which I have cut, of an age shortly after 
the closure of the neural folds, I find that the opening of the 
canal which communicates between the neural and alimentary 
canals is separated from the blastopore or anal opening by a 
projecting mass of cells, so that I think there can be no donbt 
VOL. XXVI, PART 4,—NEW SER. st 
