232 



Journal of Comparative Neurology. 



For a second determination of the number of thigh fibers, 

 counts were made of the fibers in all the crural and sciatic 

 branches which innervate the tissues of the thigh. The num- 

 bers obtained by this enumeration are given in Table IV. In 

 the comparison of the number of thigh fibers for frog B, 2600 

 fibers for the left side, 2623 fibers for the right side, with the 

 number for the shank and foot, left side 2974 fibers, right side 

 2868 fibers, is found the verification of the statement that the 

 thigh fibers are fewer in number than those innervating the re- 

 mainder of the leg. 



When the calculated number of fibers to the thigh — left 

 side 241 1 fibers, right side 2405 fibers — is compared with the 

 number ascertained by direct count — left side 2600 fibers, right 

 side 2623 fibers — the number determined by count is found in 

 each case to surpass by about two hundred fibers the estimated 

 number. This surprising disparity in the case of frog B led to 

 a repetition of the enumeration of the fibers for a second frog 

 C, lest some mistake in counting or some flaw in technique 

 might have resulted in an error. For the second frog also, the 

 number by count was found to exceed by about two hundred 

 fibers that determined by estimation. The actual number for 

 frog C is shown in Table IV to be 2777 fibers for the left thigh, 

 2814 fibers for the right thigh, while the calculated number. 

 Table III, is only 2586 fibers for the left side, 2643 fibers for 

 the right side. 



3. Significance of the disparity between the computed and the 

 actual number of fibers. 



This disparity, consisting in an excess of actual, over com- 

 puted fibers, is shown in Table V. 



TABLE V, 

 Comparison of the calculated and the actual number of fibers to the thigh 

 with the numerical excess of the latter. 



