The principal forms of the skeleton and the teeth as the basis for a system of natural history and comparative anatomy
Richard Owen
Paperback
(RareBooksClub.com, March 6, 2012)
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1859 Excerpt: ... the presence of hind-limbs, a sacrum is now established, the characters of the above five kinds of bodyvertebrae, as defined in man and other mammals, may here be given: the cervical or neck vertebra "havo perforated transverse processes," the dorsal vertebrae " bear ribs;" the lumbar vertebrae " have imperforate transverse processes and no ribs;" the sacral vertebrae "are anchylosed together;" the rest are caudal vertebrae whatever their modifications. In the above characters, the term " rib" is given to the vertebral element called "pleurapopbysis," when this is long and moveable; that element may be, and often is, present, but short and fixed, in both cervical, lumbar, sacral, and caudal vertebra; in some mammals, e.g., monotremes, the pleurapophysis may remain unan-J chylosed in some of the neck-vertebrae, but it is short, like a transverse process; and the so-called "perforated transverse process" in all mammals consists of the diapophysis, parapophy sis, and pleurapophysis; the hole being the interval between those parts: in the lumbar vertebrae the pleurapophysis is short, and confluent or connate with the diapophysis. Returning to the skeleton of the walrus, we find that nine pairs of ribs directly join the sternum, which consists of eight bones. The transverse processes of the last cervical are imperforate, consisting of the diapophysis only. The neural arches of the middle dorsal vertebrae are without spines and very narrow, leaving wido unprotected intervals of the neural canal. The bones of the neck are modified to allow of great extent and freedom of inflection. The perforated transverse processes of the third to the sixth cervicals inclusive are remarkable for the distinctn...