384 



fv 



7^ 



4-5 

 4-0 

 3-5 

 3-0 

 2-5 

 2-0 

 1-5 

 1-0 

 0-5 



^^J ^5 6- 7 8 3 



Fig. 185 

 Graphs illustrating the degree of proliferation in the spinal cord and in the dorsal- 

 root gangliaof the trunk region of axolotl larvae. Abscissae, trunk-segments 3 to 9. 

 Ordinates, weight as estimated by wax model reconstructions of the various 

 regions. Graph a. Weight of entire spinal cord in segments indicated. Graph h. 

 Weight of grey matter of spinal cord in segments indicated. Graph c, Weight of 

 dorsal-root ganglia in segments indicated. Curve A (full line), normal larva; 

 curve B (broken line), larva in which the fore-limb was grafted farther back and 

 innervated from segments 5, 6 and 7 ; Curve C (dotted line), larva in which spinal 

 cord segments 7, 8 and 9 were substituted for segments 3, 4 and 5. Note that 

 the motor cell-area (ventral region of grey matter of spinal cord) is little or not 

 affected by interchange of segments or transposition of limb, but that the sensory 

 cell-area (dorsal-root ganglia) is markedly affected by transposition of limb. 

 (From Mangold, Ergebn. der Biol, in, 1928; after Detwiler.) 



