HOMOLOGIES OF CERTAIN MUSCLES OF THE SHOULDER-JOINT. 113 



('Shoulder-Girdle/ 1868, pp. 142, 192), certain of the problems of 

 morphology in plainer language than those of most other animals. 

 It was whilst dissecting these and other animals in the light fur- 

 nished me by Mr. Mivart's papers on the myology of the Echidna 

 hystrix (' Trans. Linn. Soc' xxv. 1 866) and the Iguana (' Proc. Zool. 

 Soc' June 27, 1867) 1 that I came to entertain the views which 

 I now put forth, and in which I should have more confidence if 

 I knew them to be in accordance with his views. 



The pectoralis secundus s. levator humeri of ordinary birds arises 

 from a greater or less extent of the keel and lateral portions of 

 their sternum ; and narrowing into a tendon as it passes along the 



1 In the former of these two papers (at p. 395) a very extensive, if not exhaustive, 

 bibliography was given of the many disquisitions which had previously appeared on the 

 subject of the Homology of the limbs and their muscles. To Mr. Mivart's list the 

 following memoirs may be added, most of which are either contemporaneous with or 

 posterior in date to his paper : — 



Hermann Pfeiffer, 'ZurvergleichendenAnatomie des Schultergeriistes,' Giessen, 1854. 



Professor Haughton, ' On the Muscular Anatomy of the Crocodile,' 'Proceedings of 

 the Royal Irish Academy,' June 26, 1865 ; 'Ann. and Mag. of Nat. Hist.' Ser. iv. 

 No. 4, April 1868. 



Dr. Macalister, ' On Irregularity in the Muscles of the Shoulder,' and ' On the 

 Homologies of the Flexor Muscles of the Vertebrate Limb,' ' Journal of Anatomy and 

 Physiology,' May 1867 ; 'On Muscular Anomalies, and their bearing on Homotypical 

 Myology,' 'Proceedings Royal Irish Academy,' December 9, 1867; 'Contributions 

 towards the formation of a correct System of Muscular Homologies,' ' Ann. and Mag. 

 of Nat. Hist.' Ser. iv. No. 5, May 1868. 



Dr. Hair, ' On the Arrangement of the Muscular Fibres of the Alligator,' ' Journal 

 of Anatomy and Physiology,' November 1867. 



Professor Pagenstecher, ' Ein Vergleich der Muskulatur des Drill mit der des 

 Menschen,' ' Der Zoologische Garten, Zeitschrift fur Beobachtung, Pflege und Zucht 

 der Thiere,' April and May 1867, Frankfort. 



W. F. Vrolik, 'Den Carpus der Zoogdieren,' 1866, Leiden. 



Wood, 'Varieties in Human Myology,' 'Proc. Roy. Soc' vol. xiii. p. 299 (June 16, 

 1864), vol. xiv. p. 385 (June 1865), vol. xv. p. 239 (June 1866), p. 524 (May 1867) ; 

 ' The Comparative Anatomy of the Muscles of the Shoulder,' ' Journal of Anatomy 

 and Physiology,' November 1866. 



Jeffries Wyman, ' On the Symmetry and Homology of Limbs,' ' Proc. Boston Nat. 

 Hist. Soc' vol. xi. June 1867, ibique citata. 



My thanks are due to Messrs. Vrolik, Mivart, Haughton, Wood, and Wyman, for 

 their courtesy in sending me copies of their papers, several of which were thus 

 rendered accessible to me much earlier than they otherwise would have been. Mr. 

 Parker's magnificent volume on ' the Shoulder-Girdle,' recently (1868) published by 

 the Ray Society, furnishes, here and there, hints and guidance for the determination 

 of muscular homologies which no writer can for the future afford to ignore. One of 

 the many pleasing fruits of studying this work is the feeling that by so doing one has 

 fairly earned a right to spare one's self the task of criticising views which must have 

 been formed before Mr. Parker's labours were published. 



I 



