42 
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 (Sula Bassanat); and a more constant cutaneous muscle, viz, that which 
supports the crop in Gallimaceous birds, is briefly mentioned and figured by Hunter}. 
In the Apteryz, 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 the 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 (Pl, X. XIII. 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 the 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. 
Use.—To brace the cervical integument, raise the neck feathers, and in combination 
with the following muscle to shake these parts. 
Sterno-cervicalis (Pl. X. 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 lines, ascend upon the sides of the broad base of the neck, and are 
inserted by a thin but strong fascia into the median line 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. 
Obs—In its position and the general course of the fibres, this muscle is analogous to 
© Nitzsch, art. Dermorhynchi, Ersch und Griiber’s Encyclopedie. 
| Proceedings of the Zoological Society, 1832, p. 91. 
+ In description of pl, 10, vol. i. of Physiological Catalogue of Hunterian Collection, 4to. 1833-1841, 

