TRANSPLANTATION OF LIMBS IN AMBLYSTOMA 



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cles were supplied by a plexus derived from the ventral rami of 

 the second, third, and fourth spinal nerves (fig. 8), the latter 

 two of which are normal limb nerves. It is seen that the distal 

 portions of the nerves have grown anteriorly to effect connection 

 wdth the heterotopic limb. The typical course of the third and 

 fourth nerves is shown in figure 4. The ventral ramus of the 

 second spinal nerve, which typically unites with that of the first 

 to form the hypoglossal, is contributed almost entirely to the 

 brachial plexus. The completeness of peripheral connection with 

 the shoulder muscles is given in table 3. 



Fig. 8 Graphic reconstruction of the ventral rami of the second, third, and 

 fourth spinal nerves, showing their direction of growth and contribution to the 

 limb plexus in case AA2Si5. Arrow A indicates position of transplanted limb; 

 arrow B designates approximate level of normal limb. For normal pathways of 

 third and fourth spinal (limb) nerves (fig. 4). X 25. 



The ventrolateral musculature in this case is ahnost entirely 

 wanting. The ventral ramus of the first spinal nerve supplies 

 the fragmentary m. sternohyoideus, the anterior prolongation of 

 which is entirely wanting as is the entire m. geniohyoideus and 

 the m. genioglossus. The hyoid cartilage on the operated side 

 was also wanting. The deficient development of the m. sterno- 

 hyoideus and the complete absence of its derivatives, the m. 

 geniohyoideus and m. genioglossus, indicate that the myotomic 

 rudiments of these muscles were excised in preparing the wound 

 for the reception of the transplant. Lewis ('10) has experi- 

 mentally shown that the sternohyoid portion of the ventrolateral 

 musculature in Amblystoma is derived from the ventral processes 

 of the first three myotomes, and that, after extirpation of the 



