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pass forwards and join those of the preceding muscle, to be inserted into the scapular 
integument. 
Obs. The three preceding muscles are broad and thin, but well-defined ; they would 
appear to influence the movements of the rudimentary spur-armed wing through the 
medium of the integument, as powerfully as do the rudimental representatives of the 
true muscles of that extremity. 
There are also two muscles belonging to the cutaneous series, and inserted directly 
into the bones of the wing. One of these, the Dermo-ulnaris (Pl. X. 7%) is a small, 
slender, elongated muscle, which takes its origin from the fascia beneath the dermo- 
costalis ; its fibres pass backwards, and converge to terminate in a very slender tendon 
which expands into a fascia, covering the back part of the elbow-joint. 
Use—To extend the elbow-joint and raise the wing. 
The Dermo-humeralis (Pl. X. k) is also a long and narrow strip, deriving its origin 
from scattered tendinous threads in the subcutaneous cellular tissue of the abdomen: 
it passes upwards, outwards and forwards, and is inserted fleshy into the proximal part 
of the humerus, which it serves to depress*. 
Muscies or THE TRUNK. 
A. On the Dorsal Aspect. 
The muscles on the dorsal aspect of the vertebral column in Birds have only of late 
years received any attention from Comparative Anatomists : they have been mentioned 
rather than described by Tiedemann and Meckel: Carus has given a side-view of the 
superficial layer of muscles in the Sparrow-hawk ; their best description is contained in 
the second edition of the ‘ Lecons d’Anatomie Comparée’ of Cuvier. 
The muscles of the back are in general so feebly developed in birds of flight, that they 
were affirmed by Cuvier to be wanting altogether in the first edition of the ‘ Lecons :’ 
and this is almost true as respects their carneous portion, for they are chiefly tendinous 
in birds of flight. In the Struthious birds, and in the Penguin, in which the dorsal 
vertebre are unfettered in their movements by anchylosis, these muscles are more fleshy 
and conspicuous ; but they attain their greatest relative size and distinctness in the 
Apteryx. 
From the very small size of the muscles which pass from the spine to the scapula and 
* In Mammalia the cutaneous muscles form a more continuous stratum than in the Apteryx and other birds, 
and hence have been grouped together under the common term panniculus carnosus ; they have also, in general, 
both their origins and insertions in the integument; but in Birds, in which the integument supports so extra- 
ordinary an abundance of the epidermic material under the form of feathers, the muscles destined to its especial 
motions require a more fixed attachment from which to act. The Rhinoceros, in which the integuments, 
from the thickness and density of the corium, are in a similar condition as regards the resistance to be overcome 
by the skin-muscles, presents an analogous condition of its panniculus carnosus, having it divided into several 
distinct muscles, most of which take their origin from bone or fascie attached to bone. 
