IS 'I'HK TI»M)PHOJ?LAST OF HYFOBLASTIC ORIGIN? 585 



Is the Trophoblast of Hypoblastic Origin as 

 Assheton will have it ? 



By 



A. A. W. Iliihreclit. 



With 7 Text-fii?ures. 



In the 'Quarterly Journal of Microscopical Science' there 

 has lately appeared (vol. 54, part 2) an article by my friend 

 Asshetou^ m which he points out certain objections which he 

 feels inclined to raise agaiust some of the views that were 

 developed by me in a contribution to the fifty-third volume 

 of this Journal, entitled " Early Ontogenetic Phenomena hi 

 Mammals." 



Although I regret that he has not seen his way to comply 

 with the invitation which I addressed to my fellow-embry- 

 ologists in October, 1901 (it was published on p. 5 of my 

 article on "Tarsius" in the 'Verh. Kon. Akad. v. Weten- 

 schappen te Amsterdam/ vol. viii. No. 6, 1902), and which 

 was intended to minimise printed disputes, where personal 

 inspection of the preparations might bring about consensus 

 of opinion, still, I accept his challenge (loc. cit., p. 221), 

 and will now " discuss more fully the difficulties which have 

 arisen in the minds of some wlio are unable to accept (my) 

 theoretical conceptions." In doing so I wish to remind my 

 readers that I am not going to treat all the objections raised 

 by Assheton one by one. Many of them will remain sub lite 

 until new facts have been discovered, settling the point in 

 dispute eitlier one way or the other. I will on this occasion 



