Variation in the Muscles and Nerves of the Leg in Two Genera of Grouse (Tympanuchus and Pedioecetes)

by E. Bruce Holmes

Innervation.—The dorsal division of the femoral nerve penetrates the ventral surface.

Individual Variation.—The dorsal division of the femoral nerve may fuse proximally with either the anterior or middle division. In one leg, there are two separate branches to the muscle.

T. cupido

Individual Variation.—The insertion may not be overlapped by M. vastus lateralis. The dorsal division of the femoral nerve is fused proximally with the middle division in one leg.

P. p. jamesi

Differences from Typical T. pallidicinctus.—The fleshy origin is wider.

Individual Variation.—The dorsal division of the femoral nerve may fuse proximally with either the anterior or middle division. In one leg, there are two branches to M. iliacus, one fused with the anterior division and the other with the middle division.

M. Iliotrochantericus Medius, [Figs. 17], [20]A, B, C, D

T. pallidicinctus