90 REPORT—1848. 
restricted his examination to the dried skeleton and the still drier descriptions of 
human osteology. Had a more scientific course been pursued by the investigation 
of the neurological distribution, we feel that this error would not have been so ex- 
tensively adopted, and in fact would not have been proposed by so excellent an ob- 
server as Cuvier. Even in the skeleton of man, as best articulated, nine of the 
twelve ribs have their heads articulated opposite the intervertebral space, being 
equally connected with each of the adjoining vertebre. This we assume as the nor- 
mal position in the mammals, and even in many of the reptiles, and therefore the 
case of the first, eleventh and twelfth ribs in man are the exceptions. 
A vertebra having a rib attached, is considered dorsal in the osteology of mam- 
mals. The normal position of the head of the rib in the intervertebral space is 
beautifully displayed in the disposition of the ligaments, which in a stellate or 
divergent form unite by three tendons the head of the rib to the intervertebral car- 
tilage and adjoining vertebre: 
In the turtle this arrangement is also very well marked. As twelve ribs require 
twelve spaces and thirteen bodies to form these spaces, we require thirteen instead 
of twelve dorsal vertebrae. This will reduce the number of the cervical to six. By 
a very large induction and examination of the skeletons of recent as well as extinct 
species of mammals, we are fully satisfied, that with few exceptions, it will be found 
that there are only six cervical vertebre in the mammal class, and that this should 
be adopted as the normal type. 
The elephant was the first instance in which we observed the confirmation of what 
we had previously proposed as the true enumeration of the cervical vertebree in man, 
from a consideration of the distribution of the spinal nerves forming the brachial 
plexus. We subsequently examined the very valuable Museums of the University 
and College of Surgeons of Edinburgh, and more recently enjoyed the opportunity of 
examining those of the British Museum, College of Surgeons, and Guy’s Hospital; 
and from these and others of a more limited extent, we found that there were only 
six cel'vical vertebree unconnected with ribs, or rather that the first rib was articu- 
lated with the seventh vertebra in the following classes :—Quadrumana, from a very 
great number; Carnivora, from all-but the seals; Rodentia, Pachydermata, Pe- 
cora, Cervi, Cetacea; the only exceptions met with were the seals and one skeleton 
of a kangaroo in Guy’s Hospital Museum. In man, the first rib is occasionally in 
the normal position opposite the intervertebral space ; and when we find that the 
eighth vertebra has an undue share of costal attachment compared with all the rest, 
We may easily suppose that this has arisen from the primary branchial arch in the 
reptiloid phase of the foetus, causing the lowering of the head of the rib, thus at the 
same time producing greater horizontality in closing in the summit of the thorax, 
and giving greater freedom for the passage of the subclavian artery and vein over the 
broad surface, instead of the sharp border or edge. There is another point of view 
in which this has a bearing ; the usually defined exception of the Bradypus tridactylus 
affords grounds for the supposition that the cervical vertebre are, like those of the 
cranium, arranged in pairs, for there we have not an additional vertebra, but an 
additional pair of vertebre. In a former communication (read at the Cambridge 
meeting of the Association) we presented a sketch of the arrangement of the cranial 
vertebra in pairs as the only mode or principle of unravelling the maze.in which they 
have been so long and eyen still are involved. 
The next subject for correction is that proposed by Prof. Owen, who considers the 
scapulo-clavicular arch and anterior extremities as the divergent lamina of the occi- 
pital bone. Without attempting a full analysis and critical examination of this theory, 
we may shortly state the following objections :—I. In the mammals this is really 
composed of at least two lamine. Il. It is neurologically connected in this class 
with the lower cervical and upper thoracic or humeral region. III. It is also in the 
same position in birds and in the chelonian reptiles ; it is attached auterior to the dor- 
sal vertebra by the triquetron as a separate bone, and which is only typified by the 
triquetral or triangular surface of the spine of the scapula over which the trapezius 
plays, and to which the minor rhomboid is attached. IV. But the most striking 
objection lies in the case of fishes. The author presented to meetings of the Asso- 
ciation at Glasgow and Cambridge, proof that what had been misnamed and mis- « 
