TRANSPLANTING NEURAL TUBE OF AMBLYSTOMA 



173 



Stimulation anterior to the transplant: active movement of 

 forelimbs, followed by quick body contractions. 



Stimulation posterior to transplant: similar response. 



Stimulation at site of transplant: similar response. 



These results indicated that conduction was occurring back 

 and forth through the transplant — that functional connections 

 had been established between the transplant and the two stumps. 



Figure 10, B, shows the original anterior end of the transplant 

 in close contact with the ganglia of the ninth and tenth nerves, 

 with which a union seems to have been formed. A large process 

 passes ventrally from the transplant just in front of the pro- 



Fig. 11 Embryo T.R.5, sagittal sections 



nephros. The section shown in C, passing through the midline, 

 shows] the transplant completely incorporated in the nervous 

 system. The irregularity in the distribution of the nuclei and 

 the connective tissue septum (s) indicate the position of the 

 transplant. The fact that anatomical continuity is estabhshed 

 leads to the belief that the results of stimulation noted above 

 were due to nervous conductivity through the transplant rather 

 than to direct muscular stimulation. 



Figure 11, D, is a section passing to the right of the midline. 

 It shows a well-defined union between the transplant and the 

 brain in front. Section E passes still further to the right. The 

 transplant shows signs of diminished vigor and growth, and is not 

 connected with either stump. 



