242 JOURNAL OF COMPARATIVE NEUROLOGY. 
drawn from the original 343, leaving 228.7 to be still 
considered. 
These remaining fibers are assumed to be of the second 
class of splitting fibers (Class b), i. e., those, one division of 
which passes into the branches, while the other continues in 
the trunk below the branches. 
Since by the formula we have taken 46% of the total 
number of the fibers entering the leg (see Table XVII), we 
must assume that we took 46% of the fibers with double rep- 
resentation (Class b). It follows, therefore, that in the original 
46% or 3269 fibers, there are already included 46% of the 
fibers with double representation, or 46% of the 228.7 fibers 
which constitute Class b at this level. Therefore, to bring the 
estimated up to the observed number in this respect, there are 
still to be added to the estimated number 100%—46%=54 % 
of 228.7, which equals 123.5 fibers. In general, therefore, to 
make the estimated number comparable with that observed by 
Dr. Dunn, we should add one number representirg the fibers 
splitting in the branches (Class a), and also a second number 
representing the splitting fibers with double representation 
(Class b), in so far as they have not been included in the 
original 46%. 
TABLE XIX. 
Showing the number of fibers to be added to the original 46% in the 
case of Frog B II—Thigh. 
Calculated numbers. Observed number 
Original 46% == 209 
Fibers splitting in branches (Class a) = AGS 
Splitting fibers with double repre- 
sentation (Class b) eRe s 
3506.8 
or 3507 3508 
Difference = I fiber 
As the table shows, the estimate is almost identical with 
the observation, being but one fiber less. Without comment- 
ing on this result at this place, we shall pass on to the consider- 
ation of the nerve supply to the shank of this same leg. 
It must be kept clearly in mind that our calculation for the 
