Abstract
The present study was performed on forty adult species of chickens (galliformis), ducks (Anseriformes) and pigeons (columbiformis), with different of both sex, apparently healthy for description. The present study was undertaken to compare the gross features of the bones of pectoral limb of the examined birds to correlate their morphological peculiarities with its possible function. In this study, chickens, ducks and, pigeon, were investigated as three different habitant groups walking, flying and swimming respectively. All the bones were comparatively stronger in ducks and pigeon which could be an adaptation towards the functions necessary to perform the flight stroke. The wing skeleton was formed by the humerus, a thick radius paired with a thinner curved ulna, ulnar and radial carpals, carpometacarpal, and three digits. Pieces of the bones and muscles were processed for histological examination. Pectoral muscle fragments were collected carefully in a 10 % formalin for histology examination, and the wings were cleaned to study the bones and muscles. The arterial blood supply of the wing in domestic chickens was studied to investigate the course and distribution of the subclavian artery. The birds were slaughtered and the subclavian artery of five chickens was cannulated and flushed with warm normal saline (0.9%), then injected with red gum milk latex. The specimens were subjected to fine dissection to demonstrate the origin, course, relations and distribution of the subclavian artery. The other three chickens injected with Urograffin for x -ray purposes. The arterial supply of the thoracic limb of the fowl was formed mainly by the pectoral trunk and axillary artery. The obtained results were photographed, described. The arterial supply of the thoracic limb of the fowl was formed mainly by the pectoral trunk and axillary artery.

Key words: wing, avian, macro and micro architecture