TRANSPLANTING NEURAL TUBE OF AMBLYSTOMA 



169 



to the transplant. There is much reason to beUeve that definitive 

 union does not take place until actual nerve fibers develop. 



Figure 5 and figure 6, B, show sketches of embryo T. R. 3, 

 belonging to the same series as the preceding. Twenty days 

 after the operation {A), there is scarcelj^ any visible outward 

 evidence of the operation except lessened size as compared with 



Fig. 6 Embryo T.R.3. B, May 17; C, sagittal section. A, control, t.n., 

 transplanted neural tube. In this and all subsequent drawings of sections the 

 shaded parts represent cartilage. 



the control. Five days later {B), a shght transverse swellmg 

 appeared at the site of operation, which became more marked 

 a week later (C). Finally (fig. 6, B), thirty-seven days after the 

 operation, the transverse ridge became well defined and projected 

 slightly beyond the line of the body on the right. At this point 

 the animal was killed and fixed. In this embryo there was 

 practically no ventral bending of the body; the animal maintained 

 an upright position and was very active. Its body length was 



