The development of functional innervation in the chick wing-bud following truncations and deletions of the proximal-distal axis.

Selections of the proximal-distal axis were removed so as to produce wings lacking entire skeletal levels. The innervation of the resulting limb from the appropriate spinal nerves was tested by electrophysiological recording, gross dissection and serial sections. Ther nerves form repeatable and ordered patterns in the modified limbs which can be readily related to the normal pattern. In general the segmental nerves only innervate their appropriate territory irrespective of its location; the route followed by the nerves is characteristic for the skeletal level they traverse. If a target is missing then so is the normal nerve branch to that region.