THE NUMBER AND SIZE OF THE NERVE FIBERS 

 INNERVATING THE SKIN AND MUSCLES OF 

 THE THIGH IN THE FROG (RANA VIRESCENS 

 BRACHYCEPHALA, COPE). 



By Elizabeth Hopkins Dunn, M.D., 



{From the Neurological Laboratory of the University of Chicago.) 



CONTENTS. 



Section I. Gross Anatomy of the Muscular and Cutaneous Nerves 

 OF THE Thigh. 



A. Comparison of Rana virescens with Rana esculenta and Rana temporaria. 



B. Review of the accounts given in successive editions of Ecker's Anatomy of 



the Frog, 

 Section II. Number and Size of the Nerve Fibers Innervating the 

 Thigh. 



A. Introduction. 



1. Levels at which the computations were made. 



2. Methods of observation. 



a. Enumeration. 



b. Determination of areas. 



B. Number of Fibers, 



1. Comparison of the numbers for the right and the left sides. 



2. Relation of the number of fibers innervating the thigh to the 



number which innervates the remainder of the leg. 



3. Significance of the disparity between the computed and the ac- 



tual number of fibers innervating the thigh. 



4. Proportion of the number of cutaneous to the number of mus- 



cular fibers. 



5. Relation of the number of cutaneous fibers to the cutaneous 



area innervated. 



C. Size of Fibers. 



1. Average area for each fiber innervating the thigh. 



2. Comparison of the areas for muscular and cutaneous fibers. 



3. Average area for each fiber innervating the shank and foot. 



4. Comparison of the average area for the fibers to the thigh with 



that for the fibers to the shank and foot. 



