23 
cellular tissue, devoid of fat; the under surface is more loosely con- 
nected with the subjacent parts by a more abundant and finer cellu- 
lar tissue. 
Use.—To brace the cervical integument, raise the neck feathers, 
and in combination with the following muscle to shake these parts. 
Sterno-cervicalis.—Origin. Fleshy, from the posterior incurved 
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 diverging 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 anterior 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 that which supports and assists in emptying 
the crop in the common fowl; but the cesophagus presents no par- 
tial dilatation in the Apteryx, and the situation of the crop is occu- 
pied by a large mass of fat enclosing one or two absorbent glands. 
Sterno-mazillaris.—This muscle appears at first view to be the 
anterior continuation of the preceding, but is sufficiently distinct to 
merit a separate description and name. Origin. Fleshy; from the 
' anterior part of the middle line of the sternum. Jns. It passes di- 
rectly forwards along the under or anterior part of the neck, expand- 
ing as it proceeds, and gradually separating into two thin symme- 
trical fasciculi, which are insensibly lost in the integument covering 
the throat and the angle of the jaw. It adheres pretty closely to 
the central surface of the constrictor colli, along which it passes to 
its insertion. 
Use.—Yo retract the fore-part of the skin of the neck, and also 
the head. Each lateral portion acting alone would incline the head 
to its own side: the whole muscle in action would bend the neck ; 
but the movements of the head and neck are more adequately and 
immediately provided for by the appropriate deeper-seated muscles, 
and the immediate office of the present muscle is obviously connected 
with the skin. Nevertheless, in so far as this muscle acts upon the 
head, it produces the same movements as the sterno-mastoideus in 
Mammalia ; and it is interesting to observe, that in the long-necked 
Ruminants (as the Giraffe), the sterno-mastoid muscles arise by a 
common origin, and the insertion is by an extended fascia into the 
angles of the jaw: I consider, therefore, that the sterno-mastoid is 
represented by the sterno-mazillaris in the Apteryz, the only bird in 
which this muscle has hitherto been described. 
Dermo-transversalis.—The skin covering the dorsal aspect of the 
lower two-thirds of the neck, besides being acted upon by the con- 
strictor colli, is braced down by a thin stratum of oblique and some- 
what scattered fibres, which take their origins by fascie attached to 
