NOTES ON THE DEVELOPMENT OF THE NEWT. 573 
Notes on the Development of the Newt 
(Triton Cristatus). 
By 
Alice Johnson, 
Demonstrator of Biology, Newnham College, Cambridge. 
And 
Lilian Sheldon, 
Bathurst Student, Newnham College, Cambridge. 
With Plates XXXIV, XXXV, and XXXVI. 
THE present paper is a continuation of some observations 
made by one of us on the early development of the Newt (14). 
It was then shown that the blastopore of the embryo becomes 
the permanent anus. 
The same discovery has since been made in the Frog by Mr. 
Spencer (21), in Petromyzon by Mr. Shipley (20), and in 
Ceratodus by Mr. Caldwell (6). Dr. Gasser stated the same 
fact with regard to Alytes obstetricans in 1882 (8), in a 
paper with which the present writers have only recently 
become acquainted. 
Tur Post-Anaut Gut, 
The existence of a post-anal gut in the embryos of many 
Vertebrates appears at first sight an important argument 
against the view of the identity of the blastopore with the 
anus, because it would naturally be supposed that the blasto- 
pore must be at the extreme hind end of the gut. We find, 
however, that a post-anal gut is present in the Newt embryo, 
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