Volume 1

General and descriptive anatomy of the domestic animals / by John Gamgee and James Law.

Date:
1861-1862
Catalogue details

Licence: Public Domain Mark

Credit: General and descriptive anatomy of the domestic animals / by John Gamgee and James Law. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    the true liomologue of the human amis, and the fore-limbs of other mammals, are attached to the occipital bone. Parietal vertebra.—The centrum of this segment is the posterior Parietal, division of the body of the sphenoid bone; the posterior aim of the same bone form its neurapophyses, and the parietal bones its neural spine. These together form an enormous neural ring, varying in size with the dimensions of the cranial cavity. The haemal arch is very rudimentary, being represented by the hyoid bone. The cornua, in arch0 this case, correspond to the pleurapophyses, and haemapophyses, while the body represents the haemal spine. Every one must be struck by the marked contrast exhibited between this and a vertebral segment from the dorsal region. The incomplete and fragile haemal arch differs widely from the well-developed lib and sternum, while, on the other hand, the enormous plates enclosing the cranial cavity shows a variation little less remarkable, from the constricted neural arch of that part. Frontal vertebra.—This segment, placed between the cranium and frontal, face, has the anterior segment of the body of the sphenoid for its cen- trum, its anterior alae for its neurapophyses, and the frontal for its neural spine. The haemal arch is more developed in this segment Lower jaw than in the parietal, the pleurapophyses being represented by the lien h,ilia>a squamous portion of the temporal bone, and the haemapophyses and haemal spine by the inferior maxillary. This last portion is consider- ably altered, to serve as an organ of mastication. Nasal vertebra.—The divisions of this segment are, perhaps, some- Nasal, what obscure. Its centrum, the vomer, is enormously elongated in the lower animals, and flattened from side to side, constituting the basis of the nasal septum. The neurapophyses, blended together in this case, are represented by the perpendicular plate of the ethmoid, while the neural spine formed by the nasal bones is much elongated, and projects anteriorly to close the superior part of the nasal fossae. The haemal arch is made up of the palatine, and the maxillary „ , , bones of the upper jaw, the former being the pleurapophyses and the is upper jaw. latter, the haemapophyses and haemal spine. In this vertebra it will be observed that no neural arch exists, and at the same time the haemal arch has undergone extraordinary modi- fications, to fit it for its peculiar situation and functions. This view of these different parts is not devoid of interest, showing as it does the preservation of the different segments in their integrity, so far as the primitive vertebral type is concerned, co-ordinate with