1898 - 99 .] Dr Kennedy on Co-ordinated Movements. 637 
the peripheral segment, before reunion by means of suture, was 
twisted so as to bring the maximum number of non-corresponding 
nerve fibre ends into juxtaposition, while in the third experiment 
reunion was made as accurately in the old position as possible. 
The object of this was to ascertain : — 
1st. If the time taken for the first evidence of recovery of 
co-ordinated movements, and the course of development of the 
same, were identical or different in the two cases. 
2nd. If the resulting cicatricial nerve segments showed micro- 
scopically any important differences in the arrangement of the 
nerve fibres. 
In all three experiments, the animal being anaesthetised, the 
sciatic nerve was divided at the level of the trochanter ; but in 
the first two, before coapting the two ends by suture, the peripheral 
segment was rotated to the extent of a semicircle. Thus, on 
coaptation, the fibres of one side of the central segment were 
brought into apposition with fibres with which formerly they did 
not connect, i.e., the fibres of the opposite side of the nerve. In 
the third experiment the nerve was divided at the same point, 
and accurate coaptation in the old relationship effected by suture. 
The following is the course which the experiments exhibited, 
with reference to recovery of function. 
Exp. I. — Division of sciatic nerve at level of trochanter : rotation 
of 'peripheral segment to extent of semicircle and suture. 
Until the 7 th day after the operation, the animal showed no 
sign of returning function. It walked on the limb, which was 
supported by plaster of Paris bandages. The paw was left 
unsupported for examination purposes, and until the 7th day, 
while the animal walked on the limb, the paw was dragged along 
the ground dorsal surface down. But on the 7th day the paw 
was first used normally in walking, the plantar surface being 
placed correctly on the ground. This was taken as evidence of 
returning co-ordinated movements. Frequently, while walking, 
the paw turned over, and the animal rested on the dorsal surface, 
but on these occasions the normal position was voluntarily regained 
after a step or two. 
