Crail

“ In the living rabbit this hollow space is filled up with the brain. The skull, in fact, is a box of bone to hold the brain, a bony brain-case. This bony case fits on to the top of the vertebræ of the neck in such a way that the rounded opening we spoke of just now is placed exactly over the top of the tunnel or canal formed by the rings or arches of the vertebræ. If you were to put a wire through the arch of the lowest vertebra, you might push it up through the canal formed by the arches of all the vertebræ, right into the brain cavity. ”

“ This groove, therefore, indicates the line of separation between that part of the cranial cavity which contains the cerebrum, and that which contains the cerebellum; and as the brain exactly fills the cavity of the skull, it is obvious that the relations of these two parts of the cranial cavity at once informs us of the relations of their contents. ”

“ As the growth of bone is more active in infancy and youth than in the adult, the adhesion between the dura mater and the cranial bones is greater in early life than at maturity. From the inner surface of the dura mater strong bands pass into the cranial cavity, and form partitions between certain of the subdivisions of the brain. A vertical longitudinal mesial band, named, from its sickle shape, falx cerebri, dips between the two hemispheres of the cerebrum. ”

“ The new doctrine he expounded was received in Germany with great enthusiasm by the school of the philosophers of nature. The author conceived the cranium to consist of three vertebræ, and the basal occipital, the sphenoid, and the ethmoid, were regarded as the central parts of these cranial vertebræ. On these alleged bodies of vertebræ, the arches enveloping the central parts of the nervous system were raised, while on the opposite side were attached the inferior pieces, which went to form the vegetative arch destined to embrace the intestinal canal and the large vessels. ”

“ A human skull, with the brain scooped out, but the red scalp, and part of the hair, and the flesh of the face adhering to it, while the lower jaw had been torn away, was hung round this horrible-looking image's neck. ”

“ Nor should we be justified in regarding the cranial conformation as perhaps representing the most savage primitive type of the human race, since crania exist among living savages, which, though not exhibiting such a remarkable conformation of the forehead, which gives the skull somewhat the aspect of that of the large apes, still in other respects, as for instance in the greater depth of the temporal fossæ, the crest-like, prominent temporal ridges, and a generally less capacious cranial cavity, exhibit an equally low stage of development. ”

“ The skull consists of a cartilaginous cranium, and of jaw and visceral arches. The cranium persists throughout life, in what closely resembles a transitory embryonic condition of the higher types. There is a nasal capsule (na.c.) , a brain case proper, and lateral otic (auditory) capsules (ot.c.) containing the internal ear. (This should be compared with the frog's embryonic skull.) The upper jaw has a great bar of cartilage, the palato-pterygoid, as its sole support; the arch of premaxilla, maxilla, jugal, and squamosal-- all membrane bones-- is, of course, not represented. ”

“ In the process of flattening the head, there is often another form of crib or cradle, into which the child is placed, much in the form of a small canoe, dug out of a log of wood, with a cavity just large enough to admit the body of the child, and the head also, giving it room to expand in width; while from the head of the cradle there is a sort of lever, with an elastic spring to it that comes down on the forehead of the child, and produces the same effects as the one I have above described. ”

“ Most conservative of all has been the structure of the cranial region of the skull, that surrounding the brain, and in consequence it furnishes the most reliable characters for the discrimination of the larger groups, the subclasses or superorders. ”

“ I fell on my forearms and head, among thorns, and rose with a torn ear and bleeding face. I had fallen into a precipitous ravine, rocky and thorny, full of a hazy mist which drifted about me in wisps, and with a narrow streamlet from which this mist came meandering down the centre. ”

“ Lastly, with relation to their Use; some serve to support and carry the whole Body, as the Leg-Bones, and others are appointed to grind the Meat, as the Teeth; or else to form some Cavity, as the Skull-Bone, and those of the Ribs.
What are the Parts to be distinguished in the Bones?
They are the Body, the Ends, the Heads, the Neck, the Apophyses, the Epiphyses, the Condyli or Productions, the Cavities, the Supercilia or Lips, and the Ridges.
The Body is the greatest Part, and the middle of the Bone; the Ends are the two Extremities; the Heads are the great Protuberances at the Extremities ”

“ If we take a transverse section of the bones of the cranium, we find that they are formed of two very thin layers of bone united by a porous, osseous substance; the external layer is in direct contact with the muscles of the scalp, and the internal layer with the brain. ”

“ The brain is protected from injury by moderate degrees of violence applied to the head, by the dense and mobile scalp, the dome-like shape of the skull, the elasticity of its outer table and the buffer-like sutural membrane between the numerous bones of which it is composed, and the various internal osseous projections with the membranes attached to them, all of which tend to diminish vibrations and to disperse forces so that they expend themselves before they reach the brain. ”

“ Before you leave that wisely constructed neck, I want to press and imprint on your minds in the strongest terms that the wisest anatomist, and physiologist, the oldest and most successful Osteopath knows only enough of the neck, and its wondrous system of nerves, blood and muscles and its relation to all above and below it, to say, "From everlasting to everlasting thou art great, O Lord God Almighty!" ”

“ The complicated organ of hearing is protected by a winding series of minute apartments, in the rock-like portion of the temporal bone. The socket for the eye has a jutting ridge of bone all around it, to guard the organ of vision against injury. Grooves and canals, formed in hard bone, lodge and protect minute nerves and tiny blood-vessels. The surfaces of bones are often provided with grooves, sharp edges, and rough projections, for the origin and insertion of muscles. ”

“ On looking at the skull we find its base or occipital portion forming a right angle with the obliquely rising upper surface, and a bold transverse ridge is formed by the union of the occipital to the parietal bones, which latter advance above the frontal bones, and form the most elevated portion of the skull. ”

“ The head contains the brain and accessory ganglia, the mouth or buccal cavity, also the air-sacs in many winged forms, and gives support to the external organs of sense, the antennæ, and to the buccal appendages, the larger part of the interior being filled with the muscles moving these structures. The solid walls of the head serve as a lever or support for the attachment of these muscles, especially those of the mandibles. ”

“ It will be obvious, from an inspection of the diagrams, that the basicranial axis is, in the ascending series of Mammalia, a relatively fixed line, on which the bones of the sides and roof of the cranial cavity, and of the face, may be said to revolve downwards and forwards or backwards, according to their position. ”

“ Skull rather depressed; brain-cavity nearly as long as the beak, depressed, much expanded on the sides, with a very deep notch on the middle of each side over the condyles of the lower jaw, and with a subtriangular crown-plate. The nose as broad as the expanded brain-cavity at the base, regularly attenuated to a fine point in front, and slightly arched downwards. ”

“ The cranial end of the centrum is convex and looks ventrocraniad when the centrum is horizontal. These peculiarities are more marked in the third vertebra than in the seventh. The spinous processes grow rapidly shorter as we pass craniad; the fifth, sixth, and seventh are directed dorsocraniad, the third and fourth dorsad.
Fig. 10.—Cervical Vertebræ, Side View.
a, spinous processes; b, cranial articular processes; c, caudal articular facet; d, intervertebral foramina; e, transverse process proper; f, processus costarius; g, wing of the atlas; h, dorsal arch of the atlas; i, atlantal foramen. ”

“ If we examine the structures underlying the skin, we find that in the skull the orbits are entirely shut in by a bony wall, so that the finger cannot be passed into the temporal depression behind, as could be done in the Lemurine skull, and that the lachrymal foramen opens within the cavity for the eye. ”

“ Brain cavity absolutely larger, and, in proportion to the size of the body, much more capacious than in the Simiidæ, yet less so than in the Hominidæ. Capacity of the skull about two-thirds the average of that of man. ”

“ In the interior of the skull should be noticed a large plate of bone which extends inwards and separates the great brain, or cerebrum, from the lesser brain, or cerebellum, and prevents the jarring of that important organ likely to arise from the animal’s vigorous movements. ”

“ The stress and strain which the advancing head undergoes, and the consequent moulding and overlapping of the various segments of the skull, exposes the brain to great alterations of pressure, and throws considerable tension on the intracranial veins. ”

“ Before, however, proceeding to discuss the effects produced on the base of the skull, it is necessary to add that nature provides other methods by means of which the intensity of a blow, delivered over the vertex of the skull, is diminished. ”

“ To an anatomical eye the posterior part of the skull is even more striking than the anterior. The occipital protuberance occupies the extreme posterior end of the skull when the glabello-occipital line is made horizontal, and so far from any part of the occipital region extending beyond it, this region of the skull slopes obliquely upward and forward, so that the lambdoidal suture is situated well upon the upper surface of the cranium. ”

“ A large proportion is embedded in the bone sockets of the skull, and is hollow for some distance up in a conical form, the hollow becoming less and less as it is prolonged into a narrow channel which runs along as a thread or as it is sometimes called, nerve, towards the point of the tooth. ”

“ These structures, underlying the skull, are all that appear [s] at first of the brain box. In front, and separate from the cranium, are the nasal organs (n.c.) ; the eyes lie laterally to the trabeculae, and laterally to the parachordals are two tracts of cartilage enclosing the internal ear, the otic capsules. ”

“ Remissions and intermissions of both local and general symptoms are frequently observed, paralyses, for example, fluctuating in depth and character.
B. The bones comprising the vault of the skull become greatly thinned and widely separated from one another, the fontanelles enlarged, and the sutures unduly prominent. The head becomes enlarged in all directions, and its increased weight renders the child incapable of retaining postural control, the head being top-heavy and falling about in all directions. ”