CONNECTED WITH THE SHOULDER- JOINT. 131 



infraspinatus differentiated from a supraspinatus in either bird, 

 saurian, or crocodile. But both these latter classes possess the 

 muscle which, with the origin of the teres minor, has the insertion 

 of the teres major, and is called ' subscapulo-humeral ' by Macalister 

 ('Proceedings Royal Irish Academy,' December 1867) and Wood 

 (* Proceedings Royal Society,' May 23, 1867, p. 534)? 'infraspinatus 

 secundus ' by Professor Haughton, ' teres major ' by Stannius 

 (' Zootomie,' ii. p. 128, 2nd ed.), and, finally, ■ teres minor' by many 

 anatomists, though incorrectly, if the insertion is to determine the 

 name and nature of a muscle rather than its origin. Meckel (' Ver- 

 gleichend. Anatomie,' iii. p. 512) uses this last nomenclature, speak- 

 ing of a muscle with the origin and insertion specified as a ' teres 

 minor,' and stating that it is found in the horse, in ruminants, in 

 the ai', and in the mole. A few birds possess this accessory teres 

 major. In the common fowl it arises from the outer surface of the 

 scapula, a little way anteriorly to the downward-growing process, 

 so well marked in the gallinae and in the dodo, which receives the 

 tendon of the anterior portion of the serratus anticus. It is inserted 

 on the posterior lip of the pneumatic foramen, a point serially 

 homologous with that of the insertion of the smaller glutei of 

 human anatomy. 



This muscle is not possessed by the common pigeon, but it is 

 found in the common buzzard and sparrow-hawk, and in the goose. 

 The teres major proper is of very large size in ordinary birds ; it is 

 present in the crocodile, but absent in saurians. It is not inserted 

 with the latissimus dorsi in the sparrow-hawk, but passes to the 

 anterior lip of the entrance to the pneumatic foramen, to a point 

 just opposite to that of the insertion of the accessory teres major. 



In birds there is no praescapular region (Parker, * Shoulder- Girdle,' 

 p. 143), and consequently no supraspinatus. Indeed, as the supra- 

 spinatus of Meckel, 1. c. p. 313 (no. xv. Schoepss), receives its 

 nerve-supply from the circumflex, and must be looked upon as a 

 part of the deltoid, birds would appear to have no ' suprascapular ' 

 muscles at all, unless we may consider the deeper fibres of the 

 praeglenoid head of the levator humeri in the emu and apteryx to 

 represent such a muscle ; for there is such a muscle in the crocodile, 

 underneath the epicoraco-humeral and the deltoid, and supplied by 

 the same nerve as the former of these muscles. It takes origin 

 from the triangular surface (ss, fig. 1) intercepted between the 



K 2 



