A STATISTICAL STUDY OF THE MEDULLATED NERVE 



FIBEES INNERVATING THE LEGS OF THE 



LEOPARD FROG, RANA PIPIENS, AFTER 



UNILATERAL SECTION OF THE 



VENTRAL ROOTS. 



BY 



ELIZABETH HOPKINS DUNN. 



From the Anatomical Laboratory of the University of Chicago. 



With One Figure. 

 CONTENTS. 



PAGE. 



The material studied and tlie methods employed 685 



Distribution of the nerve branches supplying the leg of the leopard frog 



and of frog E in particular 689 



Character of the nerve branches, muscular, cutaneous or articular, in 



which medullated nerve fibers have dropped out, and comparison 



with corresponding findings for the control frog IIB 690 



Discussion of the loss of a small number of efferent medullated nerve 



fibers from the unoperated leg of frog E ; 699 



Splitting nerve fibers among the afferent medullated nerve fibers to the 



leg of the frog '. — 703 



The distribution of the muscular afferent and the cutaneous afferent 



medullated nerve fibers to the various segments of the leg of the frog. 705 

 Estimation of the number of afferent medullated nerve fibers in the leg 



of frog E, and their distribution to the segments of the leg 707 



The innervation of the foot of the frog 712 



The size of the afferent medullated nerve fibers, and the level of their 



distribution 713 



Relation of the area of the axis cylinder to the area of the medullary 



sheath in the cross sections of the largest medullated nerve fibers in 



the operated leg of frog E 716 



The Material Studied and the Methods Employed. 

 The study of the innervation of the leg of the common leopard 

 frog was begun by the author in 1898. In 1900 a report on the 

 innervation of the thigh was completed and in 1902 the material 

 had been extended to include data for the shank and foot. 



The .Tor'RN'AL of Comparative NEunoLonY axd Psychology. — Vol. XIX, No. 6. 



