Dunn, Nai'e Fibers of the Frog. 



303 



The musculature of the shank is so much more simple than 

 that of the thigh that a comparison of the different accounts of 

 the innervation of the shank as found in successive editions of 

 EcKER is not deemed necessary. But as Gaupp has introduced 

 new names for two of the six muscles of the shank, a brief 

 tabulation of the muscles as named by Ecker and Gaupp is here 

 appended. 



TABLE III. 



Gaupp's Edition of Ecker. 

 1896 — 1901 



Muscles of the calf. 



M. plantaris longus. 



M. tibialis posticus. 



Muscles of the extensor aspect. 



M. peroneus. 



M. tibialis anticus longus. 



M. extensor cruris brevis. 



M. tibialis anticus brevis. 



Ecker's Anatomic dei Froches, 1S64 

 Haslam's translation, 1889. 



M. gastrocnemius. 

 M. tibialis posticus. 



M. peroneus. 



M. tibialis anticus. 



M. extensor cruris brevis. 



M. flexor tarsi anterior. 



I. Variations appearing in successive dissections of Rana 



virescens. 



In both the thigh and the shank the order in which the 

 branches leave the main trunk presents little variation in differ- 

 ent individuals, but the number and size of the branches vary 

 more frequently in the shank than in the thigh. This condition 

 is probably due to the fact that, while in the thigh a small 

 number of large branches is given off within a short distance 

 and these large branches subdivide to innervate many muscles, 

 the branches to the shank separate at many points along the 

 course of the nerve trunks and supply single muscles or send 

 numerous branches to one muscle. 



The large number of branches sometimes given off to single 

 muscles is indicated in Table IV, which is a tabulation of the 

 muscular and cutaneous nerve branches to the shank, as found 

 in the frog designated as Frog II B, whose peripheral nervous 

 system furnished material for the data discussed at a further 

 point in this study. 



