TRANSACTIONS OP THE SECTIONS. IS? 



On the Muscles of the Extremities of Birds. 

 By Professor Carl J. Sundevald. Communicated by Professor Retzius. 



This paper contained an abstract of an extended examination of the comparative 

 anatomy of the muscles of the limbs in the various orders and families of birds in 

 further elucidation of views brought forward by the author in 1851, together with an 

 attempt to determine the homologies of these muscles with those of mammals and 

 reptiles. The author traced to variations in the skeleton many of those differences 

 in the muscles which had occasioned so much difficulty to comparative anatomists 

 in ascertaining their homologies. He remarks on the inappropriateness of many of 

 the names applied to the muscles from human anatomy, such as triceps and biceps 

 brachii, &c. The biceps he would call Vector brachii, and for the Biceps femoris, he 

 would propose the name of Puisator in connexion with its action on the foot. The 

 posterior clavicular bone of birds, usually named coracoid by recent anatomists, he 

 would propose to call obex (bolt or bar), as the coracoid is in reality only a part of 

 this bone ; and he would distinguish thus the muscles which are attached to the 

 whole bone as obical in distinction from those which are simply coracoid. 



The subclavius muscle of birds the author regards as merely an anterior part of 

 the pectoralis minor, and he adduces in proof of this view the variations of this 

 muscle in different mammals, more particularly those wanting the clavicle, in which 

 the subclavius is proportionally large and is continued on to the humerus along with 

 the pectoralis minor. 



The greater part of the cervical muscles going to the shoulder is wanting in birds, 

 such as the sterno-mastoid, omo-hyoid, &c. The muscle usually termed cucullaris in 

 birds is only an extension of the upper rhomboid, being covered by the latissimus, 

 and the fore-part of the latissimus corresponds to the dorsal portion of the true 

 cucullaris. The so-called pectoralis tertius (of Tiedemann), or coraco-brachialis 

 inferior (of Meckel), is a part of the coraco-brachial modified as in Saurians by the 

 extension of the coracoid bone. 



The large pelvic muscle of birds which extends over the patella to the tendons of 

 the perforated flexors, and has been variously considered as rectus femoris, pectineus 

 or gracilis, is called by Sundevald musculus ambiens. It is not, as has been generally 

 supposed, the means of enabling birds to sleep sitting on the branches of trees, &c., 

 as it is frequently wanting precisely in those birds which have this habit, and is 

 found, but not invariably, in the Swimmers and Waders. 



The femoro-caudal muscle is a small representative of the muscle which is so very 

 large in Saurians, and which gives the backward direction to the hind-limbs. The 

 author leaves it doubtful, whether it is, as has been supposed, the pyriformis with a 

 more extended attachment to the vertebral column. 



On the whole, the muscular system of different families of birds presents very 

 considerable varieties. The singing birds (Oscines, part of Passeres) have the 

 greatest uniformity. They are distinguished principally by the large size and extent 

 of the deltoid and the breadth of the teres minor. They have no gluteus maximus 

 and no ambiens, and the femoro-caudalis is simple. Sundevald points out, that the 

 Menura, Tyranni and Furnarii, and some other birds of doubtful systematic place, 

 have the same muscular structure as the Oscines, and should be placed under the 

 same division with them (as he proposed in 1835), but perhaps undei' a separate 

 section, as they do not possess the singing apparatus. 



In a number of the Scansores the gluteus maximus is wanting ; the ambiens and 

 femoro-caudalis variable ; the peronei deficient or very short, as also is the case in 

 Colymbus and Podiceps. 



The Raptatores have no semitendinosus and no tibialis posticus, but they possess 

 a small gluteus maximus. In Faico and Vultur the ambiens exists, but not in owls. 

 It is interesting that all the muscular peculiarities of the diurnal birds of prey are 

 found in Tachypetes, proving their close relation. 



In the Gallinee, Grallse and Anseres, the accessory head of the tensor prsealaris is 

 small. In most of them, the gluteus maximus is present, but very small. The 

 Gallinse are especially distinguished by their large subclavius, separate from the 

 pectoralis minor, by the humero-ulnaris internus peculiar to them, and by their 

 large pronators. In Wading birds there is little peculiar. The Swimming birds are 



