434 C. J. Sundev^all on the JVinys of Birds. 



The cubitus has no more than these 16 muscles. Of those 

 which occur in man there are wanting therefore : — Among the 

 extensors, three belonging to the thumb and one to the little 

 finger ; among the flexors, one to the thumb and the pronator 

 quadratus ; or all the proper long muscles of the thumb, and 

 one which could not act. Other peculiarities of the class 

 are : — The double pronator and the single supinator, the 

 course of the sinews from the flexores digitorum, fl. carpi 

 radialis, and extensor digitorum, the size of the extensor carpi 

 radialis longus and anconceus parvus (?No. 6), and lastly the 

 addition in some forms of No. 15 {humero-tdnains internus). 

 One could scarcely suppose that there would be so little 

 difference between the muscles of the bird's wing and the 

 human arm ! 



C. Muscles of the humerus, which still more resemble 

 those of man. They are : — 



17. Extensor antibrachii (or triceps), almost exactly as in 

 man, but wanting the caput internum. 



18. Flexor antibrachii (or biceps) as in man. 



The Anconceus parvus has already been mentioned, No. 6; 

 as also the Brachialis internus, No. 16. 



Of the muscles of the shoulder we shall in what follows 

 mention only the deltoideus, in order to avoid going into too 

 many specialities here ; but we will nevertheless remark that 

 equally distinct differences, as in the forearm, present them- 

 selves, between different groups of birds, in the other muscles 

 of the shoulder and those of the trunk. 



In order to make a comparison between the muscles of 

 the arm in the orders of birds, I have myself investigated them 

 in 27 species selected from all orders, and can, moreover, 

 avail myself of Schopss's excellent descriptions of 11 (four of 

 which, however, are the same) ; namely : — 



OsciNEs : Corvus corone, Schopss ; Garrulus glandarias, 

 Sell, etipse; Pyrrhula vulgaris, Emberiza citrinella, Parus 

 cristatu^, and Hirundo rustica. 



Coccyges (sensu latiori) : Cypselus apus, Picus major, 



