On the Sero -Amniotic Connection and the 

 Foetal Membranes in the Chick. 



By 



S. Hirota. Rigakushi, 



Zoological Institute, Imperial University, Japan. 



With Plates XV-XYII. 



CONTENTS. 



Introductory lîemarks. 



1 Origin of tlie Sero-Amuiotic Connection. 



2 Prolongation ni' tlie Sero-Aiuniotic Connection. 



3 Limit of tlie Prolongation. 



4 Changes in the Extra-Embryonic Germinal Layers. 



5 Pieplacement of Cells in the Sero-Amuiotic Connection. 



6 Expansion of the Mesoblastic Comiection, 



7 Perforation in the Mesoblastic Connection. 



8 Supplement to tlie Preceding Sections. 



9 Effects of tlie Sero-Amniotic Connection on the Foetal Membranes. 



10 Comparison between the Sero-Amniotic Connection in the Cliick and that 



in Chelonia. 



11 Methods for the Preparation of the Specimens. 



12 Explanation of the Plates, 



There is probably no other animn] whose development has so 

 much been Tn;ide the subject of study not only by students in <'eiieral 

 but by S[)e('iMl invesrio-nfors ns that of the chick, and, vet. it is a 

 remarkable far-t that erroneous notions jH-evail at tlie j^resent dav in 



