TRANSPLANTING NEURAL TUBE OF AMBLYSTOMA 



165 



marked difference in healing, and no constant differences were 

 noted in subsequent changes. The present account is based upon 

 a study of some fifty operations, the results of which were of a 

 uniform character. 



Figure 2 illustrates the gross changes in the form of the body 

 typical of embryos operated at stage D (fig. 1). Similar changes 

 are noted when the operation is made at earlier stages, except 



Fig. l^'A|and B, dorsal and lateral views, T. R. and T. L. series; C and D, 

 lateral views, F^and G series, respectively. Five minutes after operation. 



that the primary flexing of the head and tail toward each other 

 dorsally.is apt to be more marked when the operating is done in 

 the earlier stages. This dorsal flexure is well shown in figure 

 3, A, and is probably due to contraction accompanying the closure 

 of the wound. As may be noted in figure 2, this preliminary 

 bending is followed by a straightening of the body axis, which in 

 turn is succeeded by bending m a direction opposite to the first 

 bringing the head and tail nearer to each other on the ventral 

 side. It was found that in cases where the ventral bending was 



