CONNECTED WITH THE SHOULDER-JOINT. 135 



Postscript, Dec. 1 1, 1868. 



Several memoirs bearing more or less directly upon the sub- 

 jects treated of in this paper have appeared, or at least come into 

 my hands, subsequently to June 14th. 1868. First among them I 

 may mention the paper on ' Variations in Human Myology,' which 

 was read June 18th, 1868, before the Royal Society, by John 

 Wood, Esq., F.R.C.S. In this paper, as published in the Royal 

 Society's Proceedings, vol. xvi. no. 104, will be found an excellent 

 figure of that common modification of the pectoralis minor which 

 converts it into a more or less perfect levator humeri, so far as 

 function is concerned. But that it was not a morphological equi- 

 valent of the pectoralis secundus of the bird would have been 

 shown, I apprehend, first, by its relation to the costo-coracoid 

 membrane, and, secondly, by its innervation. Meckel, in his 

 1 Vergleichende Anatomie,' iii. p. 318, speculates as to whether the 

 bird's ' pectoralis secundus ' is to be regarded as a divarication of 

 the great pectoral, or as a specialisation of a part of the deltoid. 

 Now, as I hold that the pectoralis minor is essentially a part of the 

 pectoralis major, I should say that Mr. Wood's figure shows that a 

 levator humeri may be formed in the former of these two ways ; 

 and that such a muscle may be formed in the second of these two 

 ways also is shown by the history I have already given, pp. 

 125, 126, of the smaller levator humeri in the fowl. But that 

 the ordinary levator humeri s. pectoralis secundus of birds, which 

 coexists with the smaller levator in the fowl, corresponds, as a 

 matter of fact, to the epicoraco-humeral of the reptile and the sub- 

 clavius of the mammal, is shown by the history of its relations to 

 surrounding parts, by its nerve-supply, and by the history of the 

 development of the great pectoral. Nor does functional correspond- 

 ence enable us to argue to morphological identity here more than 

 anywhere else. 



Secondly, Professor Goodsir's ' Anatomical Memoirs ' have, since 

 last June, been published under the able editorship of his successor, 

 Professor Turner ; and in the first volume, at p. 452, may be found 

 an exposition of the views of the late great anatomist, alluded to at 

 p. 128, as to the 'morphology of the muscles of the limbs.'' With 

 reference to these views, I would remark that it seems incorrect 

 to class the obturator internus with the subscapularis, because in 



