84 
PROFESSOR WOOD ON THE NECK- AND SHOULDER-MUSCLES. 
is only surpassed by that of the muscles of the fore arm. The reason for the latter can, 
from the variety of the uses and functions of the upper extremity, be better compre- 
hended than in the case of the neck and shoulder, which would seem to demand much 
less various muscular appliances from a teleological point of view, and their varieties 
therefore might be considered to have a more decided morphological bearing. 
I will first take the varieties of one of those groups which has for its function in the 
human subject to raise the shoulder-girdle behind and before, and to rotate it on the 
central axis of the shoulder-blade. In animals, the group draws these bones forwards 
and upwards, or downwards, and they are usually more movable in them than in Man. 
In both they also act conversely upon the cephalic extremity, either directly or through 
the neck-vertebrae. In the lower animals we shall find that the muscles of the group 
frequently obtain a longer leverage by becoming connected lengthwise, or are even 
blended with other muscles or portions of muscles acting in the same direction, and so 
obtain a greater play of motion and an increased power of a more direct kind upon the 
fore limbs and head. 
We find in these muscles some of the best examples of what I have called in my 
former papers, lateral and longitudinal fission , and fusion , of adjacent muscles acting 
in the same general direction in regard to the axis of the limb. 
The normal muscles constituting this group range from as far back, and as deep, as the 
splenii and serrati, through the rhomboids , the trapezius, and the levator anguli scapula? 
to the sterno-cleido mastoideus of human anatomy. 
The abnormal human muscles include those which I have described briefly in various 
previous publications in the ‘ Proceedings of the Royal Society’ under the names of the 
occipito- scapular, the levator clavicular, and the cleido-occipital, reaching as far back as 
that division of the splenius which has been called by Walther the adjutor splenii, and 
by Macalister the rhombo-atloid. 
Occipito-scapular Muscle. — In the winter of 1866-67 I found in a muscular male sub- 
ject, on both sides, a muscle extending from the occiput to the base of the scapula, under 
the trapezius, which I described in the ‘ Proceedings of the Royal Society’ for May 1867, 
under the name of the occipito-scapular muscle. It was a distinct ribbon-shaped 
muscle, three-quarters of an inch wide, nearly a quarter of an inch thick, and 10 inches 
long (Plate IX. fig. 1, d), attached by a musculo-tendinous origin to the occipital bone 
on a level with the splenius capitis (h), and directly under the line of junction between 
the trapezius (T) and a variety of the sterno-clei do-mastoid , which was also present, 
and which I have named the cleido-occipital (c). Passing downwards and outwards, 
obliquely across the splenii, and between them and the trapezius, it became inserted 
by short tendinous fibres, superficial and opposite to the rhomboideus minor ( r ), into 
the vertebral border of the scapula opposite the base of the spine, its fibres being 
more or less blended with those of the rhomboids. 
Since that time evidences of the muscle have been sought for in fifty subjects. The 
nearest formation to the complete muscle was again found, last session, in a muscular 
