The Muscular System of the Limbs

The muscles of the limbs of Fishes are very simple, consisting, on each face of the limb, of bundles of fibres, which proceed (usually in two layers) obliquely, from the clavicle and supraolaviole to the fin-rays. The pectoral, and pelvic arches themselves are imbedded in the lateral muscles.

In the Amphibia and all the higher Vertebrata, the muscles of the limbs are divisible into - intrinsic, or those which take their origin within the anatomical limits of the limb (including the pectoral or pelvic arch); and extrinsic, or those which arise outside the limb.

Supposing the limb to be extended at right angles to the spine (its primitive position), it will present a dorsal aspect and a ventral aspect, with an anterior, or pre-axial, and a posterior, or post-axial, side.

In the Vertebrata above fishes, the following muscles, which occur in Man, are very generally represented: