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H. L. WIEMAN 



neural stumps would seem to have been very remote indeed. 

 Finally, r4, killed May 17th, was the only one of the entire 

 series that in sections showed any connection between transplant 

 and nervous system, and here the connection extended only 

 between the anterior side of the transplant and the brain. The 

 appearance of the sections does not exclude the possibility of a 

 posterior connection through the transplant being established 



Fig. 18 A, Embryo F4, May 17. Operated April 16. B, sagittal section. 



later had the embryo been allowed to live. However, the fact 

 that this had not occurred by the end of thirty-one days speaks 

 against it, since in the T. R. series both anterior and posterior 

 connections were established as early as twenty days after the 

 operation, and in the G series even earlier — seven days in the 

 case of G9 — but the latter series were much older at the time 

 of operation (fig. 1). Further, F4 was the only one of the six 

 embryos of the F series chosen at random for sectioning in which 



