278 PROF. OWEN ON THE ANATOMY 



much attention : brief notices are recorded of some peculiarly developed cutaneous, or 

 rather cuticular, muscles, as those which spread the plumes of the Peacock, erect the 

 hackles of the Cock, and make each individual feather stand on end in the web-footed 

 birds' ; the compressors of the subcutaneous air-cells are noticed in the anatomical account 

 of the Gannett (SulaBassana-); and a more constant cutaneous muscle, viz. that which 

 sujjports the crop in Gallinaceous birds, is briefly mentioned and figured by Hunter". 



In the Apteryx, however, the true cutaneous system of muscles presents a more di- 

 stinct and extensive development than has hitherto been met with in the class of Birds 

 — a condition which is evidently connected with the peculiar thickness of the integument, 

 and probably with tlie burrowing habits of this species, which thereby possesses the 

 power of shaking off the loose earth from its plumage, while busy in the act of exca- 

 vating its chamber of retreat and nidification. 



Constrictor colli (PI. XXXI. XXXIV. a). — The whole of the neck is surrounded by a 

 thin stratum of muscular fibres, directed for the most part transversely, and extending 

 from an attachment along the median line of the skin at the back of the neck, to a parallel 

 raphe on the median line of the opposite side : this muscle is strongest at its commence- 

 ment or anterior part, where tlie fibres take their origin in a broad fasciculus from the 

 outer part of the occipital ridge ; these run obliquely downwards and forwards on each 

 side of the neck, but are continued uninterruptedly with those arising from the dorsal 

 line of the skin above mentioned ; the direction of the fibres insensibly changing from 

 the oblique to the transverse. The outer surface of this muscle is attached to the in- 

 tegument by a thin and dense layer of cellular tissue, devoid of fat ; the under surface is 

 more loosely connected with the subjacent parts by a more abundant and finer cellular 

 tissue. 



jT/^e. — To brace the cervical integument, raise the neck feathers, and in combination 

 with the following muscle to shake these parts. 



Sterno-cervicalis (PI. XXXI. b). — Origin. Fleshy, from the posterior incurved angular 

 process of the sternum, from the ensiform prolongation and middle line of the outer 

 and posterior surface of the same bone. Insertion. The fibres pass forward, and, diver- 

 ging in gently curved Unes, ascend upon the sides of the broad base of the neck, and are 

 inserted by a thin but strong fascia into the median Une of the dorsal integument. This 

 muscle is a line in thickness at its origin, but becomes thinner as it expands ; the ante- 

 rior part is covered by the posterior fibres of the constrictor colli. 



Use.— To retract the skin of the neck, and brace that portion which covers the base 

 of the neck ; when these are the fixed points, it will depress and protract the sternum, 

 and thus aid in inspiration. 



0^5. — In its position and the general course of the fibres, this muscle is analogous to 



' Nitzsch, art. Dermorkynchi, Ersch und G ruber's EncycJopedie. 



- Proceedings of the Zoological Society, 1832, p. 91. 



' In description of pi. 10, vol. i. of Physiological Catalogue of Hunterian Collection, 4to. 1833-1841. 



