An introduction to the osteology of the Mammalia : being the substance of the course of lectures delivered at the Royal college of surgeons of England in 1870 / By William Henry Flower.

  • Flower, William Henry, 1831-1899.
Date:
1870
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the osteology of the Mammalia : being the substance of the course of lectures delivered at the Royal college of surgeons of England in 1870 / By William Henry Flower. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    115/364 (page 99)
    the cerebral cavity in these directions, by meeting in the middle line. These are the frontal bones. Between the middle bones of the parietal and frontal segments (alisphenoid and orbitosphenoid) is an irregular vacuity, called the foramen lacerum anterius, or sphenoidal fissure, through which several nerves pass to the orbit. This is the second vacuity in the side wall of the skull, the first being the one between the occipital and parietal segment, partially filled by the periotic bone. As the occipital segment is not closed behind, so in the same way the frontal segment is open in front, the aperture being bounded by all the bones which enter into its com- position—presphenoid, orbitosphenoids, and frontals. The hinder edge of the mesethmoid rising up to meet the frontals makes a median partition to this aperture (the crista gain of human anatomy), and it is further closed by a special ossification {CE) connected with the organ of smell, the cribrifo7-m plate. Thus the brain-case may be described as a tube, dilated in the middle, composed of three bony rings or segments, with an aperture at each end, and a fissure or space at the sides between each of the segments. The cranial cavity thus formed is of a general oval form, but broader behind than in front. The floor is compara- tively straight; the upper surface arched. It is imperfectly divided by bony ridges into three compartments. The most posterior of these, marked off in front by a sharp ridge along the periotic bone {Per), extending from near the junction of the basisphenoid and basioccipital, upwards, outwards, and backwards, along the line of junction of the parietal and supraoccipital, and strongly marked by an inward shelf like projection from the former (the ossified tentorium cerebclli), is called the cerebellar fossa, as it H 2