174 



H. L. WIEMAN 



Figure 12 is an outline of embiyo T. R. 4, an animal belonging 

 to the same series as the preceding, but not killed until May 27th. 

 For some time preceding this date responses to stimulation in-, 

 dicated that conduction paths had been established through the 

 transplanted tube. 



In figure 13, B, is seen a sagittal section passing to the left of 

 the midline. Complete anatomical continuity is evident, but 



Fig. 12 Embryo T.R.4, May 27. Operated April 8 

 Fig. 13 Embryo T.E,.4, sagittal sections 



the V-shaped configuration of the nuclei reveals the location of 

 the transplant. The section shown in C passes directly through 

 the midline, where the transplant appears to be completely 

 absorbed; but here again its boundaries are indicated by two 

 breaks or gaps in the nuclear mass. Careful examination of 

 all of the sections in the series shows that the fusion between the 

 transplant and the nervous system is very intimate, none of 

 the transplant extending beyond the lateral limits of the brain 

 and cord. 



