On the Formation of the Germinal Layers in 

 Chelonia.'* 



K. Milsukuri, Ph. D. 



Professor of Zoology, 

 and 



C. Ishikawa, 



Assistant in Zoology, 



Science College, Imperial Uuirersity. 



AVith Plate XIV, XV, XVI, and XVII. 



In the spring of 1884 we made the acquaintance of Mr. Hattori, 

 the proprietor of a large fish-hatching establishment in Honjo, a 

 suburb of Tokyo. His father before him, and he, had succeeded in 

 making the snapping turtle — Trionyx Japonicus, Schlegel — breed 

 freely and naturally in captivity, and thus in furnishing the market 

 Avith a constant and large supply of its delicate flesh. In his farm 

 hundreds of these trurtles are annually hatched, and if the eggs are 

 marked as they are laid the exact age of any given deposit can be 

 determined with great precision, even to minutes in many cases. 

 Such an opportunity for the investigation of Reptilian development 

 seemed to us too good to be thrown away, especially as nobody had, so 

 far as we were aware at the time, worked on the embryology of 



* This article was also published in Quart. Jour. Micros. Sei. No. CV (Vol. XXVII, Pt. I). 



