110 ^- MITSUKÜRI 



POSTSCRIPT. 



At the end of Jiimiary of the present year, I received from 

 Dr. Ludwig Will a copy of his article entitled " Die Anhuje der 

 Keiiiiblätter hei der Eidechse (Lncerta).''* As the foreß-oino- article had 

 then nearJy taken its final shape, it was not possible to take Dr. 

 Will's new article into consideration in the body of the article. I 

 have for this reason decided to add a postscript in order to put together 

 some remarks on Dr. Will's paper. 



While Will gave in two former papers ('92 & '93) the course 

 of development in tlie early stages of Platydactijlus and Cistiido, he has 

 in this paper given the results of his investigations on the same 

 phases in the embryology of Lacer ta. His observations begin from 

 the appearance of the primitive plate and end with the formation 

 of the mesoblast and the primitive groove. As we are for the present 

 most interested in the last part, we shall confine ourselves only to a 

 few remarks on the e;u*lier phases. 



As regards the characters of the primitive plate, and the process 

 of gastrulation Will has obtained on the whole the same results in 

 Lacerta that he obtained before in Plati/dactyhts and Cistudo. For 

 instance, he insists again on the sharp limits between the epiblast and 

 primitive pi ite (//, y in A, Woodcut II of the foregoing article). On 

 some points, however, lie gives différent results. The following are 

 some of these points : — 



(a). While insisting in general on a distinct boundary between 

 the primitive plate and the epiblast, Will confesses that he was often 

 unable to find such a limit on the posterior end of the primitive plate. 



* Zoologischer Jahrbücher, Ahth. f. Anat. u. Ont. der Thiere. IX Bd. 1895. 



