248 JOURNAL OF COMPARATIVE NEUROLOGY. 
The Jevels C+-Si,’P+T; and Pr+P2 and i112 are alam 
cated. If there were no splitting fibers the schema would be 
made up of the outlines of the three columns alone. 
Turning now to general results of this test, we find that in 
the case of the right leg of Frog B II, the estimated numbers 
agree very closely with those observed when an allowance, 
according to a fixed procedure, is made for the splitting fibers. 
The significance of this result depends largely on the 
possibility of repeating it. Using exactly the same methods, 
the results for the left leg of this frog (data presented in Table 
XV) are almost as good as those for the right. 
The following table presents the results for both legs 
Frog, Bull: 
TABLE XxXI. 
Estimation 
(DONALDSON) 
Corrected for splitting Observed Difference Percent- 
fibers (DuNN) in fibers age 
Thigh R 3507 3508 — I —.03% 
Thigh L 3497 3481 +16 +-40% 
Shank R 2116 2130 —14 —.65% 
Shank L 2110 2108 +2 +.09% 
Foot R 2497! 2497 Sere = 
Foot L 2486! 2486 set’ 
1 8¢, of the observed numbers being added to represent the splitting fibers 
with a similar distribution of both divisions—see text. 
This is the only frog we have in which the enumeration at 
different levels has been complete enough to permit of this full 
test of the formula. In Frog C II, however, the endeavor 
was made to determine whether the proportional distribution of 
the fibers at different levels in the leg would correspond with 
those found in Frog B II, for it seemed very probable that if 
the two frogs corresponded in this respect, they would also 
correspond in the number of fibers supplied to each segment 
of the leg. 
The data for Frog C II give the number of fibers entering 
the leg at C4 Si the number at S», and the number entering 
the foot, at Pr P2 4:/and Tria. T2; see Table Vi 
