Lobe (anatomy)

“ The upper surfaces of these lobes are covered with small red glands, each of which appears, when highly magnified, like a compressed arbutus berry. Among the glands, about the middle of each lobe, are three very small erect spines. When the lobes enclose any substance, they never open again while it continues there. If it can be shoved out, so as not to strain the lobes, they expand again; but if force is used to open them, so strong has nature formed the spring of their fibres, that one of the lobes will generally snap off, rather than yield. ”

“ If, however, we reject these arbitrary modes of distinguishing the various lobes, and follow a more philosophical method, for example, the one suggested by Gratiolet, a corresponding conclusion is forced upon us, viz., that all the great masses in the human brain have their anatomical representatives, or homologues, in the Chimpanzee. The frontal lobe (figs. 4 and 5) F, together with the parietal lobe P, marked off by the first ascending convolution 4,4′, which is included in the latter, lie above the Sylvian fissure, and in front of the vertical or perpendicular fissure ”

“ It is generally admitted that no very strict line of demarcation is traceable between the middle and posterior lobes; anatomists being content to accept Cuvier's curt definition:—
"La partie du cerveau située au-dessus du cervelet est ce qu'on nomme le lobe postérieur du cerveau." ”

“ Thus, every original authority testifies that the presence of a third lobe in the cerebral hemisphere is not "peculiar to the genus Homo," but that the same structure is discoverable in all the true Simiæ among the Quadrumana, and is even observable in some lower Mammalia; and any one who chooses to take the trouble to dissect a monkey's brain, or even to examine a vertically bisected skull of any of the true Simiæ, may convince himself, on the still better authority of nature, not only that the third lobe exists, but that it extends to the posterior edge of, if not behind the cerebellum. ”

“ I should be inclined to say, that the posterior lobe is little inferior to that of man, excepting, perhaps, in vertical depth. The cerebral hemispheres completely covered the cerebellum, as seen from above. I took pains to observe this while the brain was still within the cranium, looking down upon it at right angles to the longtitudinal axis of the cranial cavity, and I found the posterior extremity of the cerebral hemispheres projected a little beyond the vertical line, passing the back of the cerebellum. ”

“ As to the external anatomy, whilst too little importance has perhaps been assigned to the points of difference which the very widely-differing heights of the hemispheres, the very widely-differing antero-posterior diameters of the corpora callosa, and of the frontal lobes, and the very widely-differing absolute weights of the two brains, constitute, too much seems to have been given to the "absence of an external perpendicular fissure," to the "presence of a lobule of the marginal convolution," and to the lesser relative size of the nerves in the human brain. ”

“ Lobes: of the maxilla; see galea (outer) and lacinia (inner) : of the mentum in Coleoptera, are the lateral expansions shielding the base of the central organs.
Lobes of pronotum: in Orthoptera; the spaces or areas formed by three transverse impressions on the pronotum: that which borders the head is the anterior lobe, the hindmost is the posterior lobe, those intervening are the middle lobes. ”

“ The molars are very like those of Asmodeus, large brachydont grinders, composed of an outer wall, and an anterior and posterior lobe. The external cingulum is a trace only, and the internal cingulum is developed in varying degrees. ”

“ The upper joint consists of two lobes, each lobe is of a semi-oval form, with their margins furnished with stiff hairs, like eye-brows, which embrace or lock in each other when they are inwardly irritated. ”

“ We really see the skull pared off and the surface of the brain. The surface shows quite normal convolutions. Under a microscope some of them might, perhaps, show some differences in size and form, but now we can only see a common surface. We see, plainly also the well-known gray matter, composed of nerve-cells and deposited all along the surface in small convolutions,—and, for the benefit of laymen, I add that modern physiologists designate this gray matter as the seat of consciousness, thought, talent, and recollections. ”

“ The two lobes must be separated, and the above-mentioned experiment made with each distinctly, and any difference in the results remarked; if one lobe float, and the other sink, it should be noticed whether it is the right or left that floats. Each lobe is then to be cut into several pieces, taking care not to confuse those of the right with those of the left. ”

“ Most organic substances are transparent or semi-transparent to these rays, and hence such rays readily pass through the body of an individual, being only intercepted in part by the denser parts of the anatomy, such as the bones, so that a man in such light no longer casts a well-defined shadow of his outline, but [320] the shadow disclosed is that of a skeleton, by virtue of the greater density of the bones. Any object of higher density, such as a ring upon the finger, clearly establishes its shadow by virtue of its greater density. ”

“ The Cranial Bones.—The cranium or skull is especially adapted for the protection of the brain and the bones are flat and closely fitted to its surface. They have two layers of bone, the outer and the inner tables, of which the outer is the thicker, and between these is a tissue filled with blood-vessels, the diploë. In the infant, whose brain has not yet attained its full size, opportunity must be left for growth and the skull therefore consists of a number of bones with interlocking notched edges, where growth takes place, but in the adult it forms one solid covering of bone. ”

“ But the bones hold tight, socket and ball, and clamping them down in the hard, black ground is the stake, wedged through ribs and spine. The bones may twist, and heave, and twine, but the stake holds them still in line. The breeze goes down, and the round stars shine, for the stake holds the fleshless bones in line.
Twenty years now! Twenty long years! The body has powdered itself away; it is clay to clay. It is brown earth mingled with brown earth. Only flaky bones remain, lain together so long they fit, although not one bone is knit to another. ”

“ In the skull, besides the larger openings we have spoken of, you will find several small holes leading from the outside of the skull into the inside of the brain-case. Some of these holes are filled up during life by blood-vessels, but in others run those delicate white threads or cords which you have already learnt to call nerves. Nerves are in fact branches of nervous material running out from the brain or spinal cord. Those from the brain pass through holes in the skull, and at first sight seem to spread out very irregularly. Those which branch off from the spinal cord are far more regular. ”

“ From the histological room you are conducted to the room of elementary chemistry, in which you learn something of the laws of association of substances, that you can the better understand what has been told you in the physiological room, which is only a branch of anatomy, and intended to show you that nature can and does successfully compound and combine elements for muscles, blood, teeth and bone. ”

“ All the four elements entered into the original composition of the human frame; the bone was formed out of smooth earth; liquids of various kinds pass to and fro; the network of fire and air irrigates the veins. Infancy and childhood is the chaos or first turbid flux of sense prior to the establishment of order; the intervals of time which may be observed in some intermittent fevers correspond to the density of the elements. The spinal marrow, including the brain, is formed out of the finest sorts of triangles, and is the connecting link between body and mind. ”

“ Each orbital cavity is formed by the juncture of some seven bones and communicates with the cavity of the brain through the optic foramen and through the sphenoidal fissure. Above the orbits are arched eminences of skin, the eye-brows, from which several rows of short hairs grow longitudinally and which serve to protect the eyes and to limit the amount of light to a certain extent, as in frowning. ”

“ 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 spinal cord, like the brain, consists of gray and white matter, but the arrangement differs. In the brain the white matter is within, and the gray matter is on the surface. In the cord the gray matter is arranged in two half-moon-shaped masses, the backs of which are connected at the central part. The white matter, consisting mainly of fibers, running for the most part in the direction of the length of the cord, is outside of and surrounds the gray crescents. ”

“ Is the Brain which is preserv'd in the Skull all of one Piece, or one equal Mass?
No, it is distinguish'd by the means of the Meninges into the Brain it self, and the Cerebellum or little Brain; the Brain, properly so called, takes up almost the whole Cavity of the Skull, and the Cerebellum is lodg'd altogether in the hinder-part, where it constitutes only one entire Body; whereas the former is divided into the Right and Left Parts by the Meninges, which cut it even to the bottom; whence these Foldings are call'd Falx ”

“ The intelligence and all the special senses, except the sense of touch already spoken of, are gathered together compactly in the head, where they are carefully protected with bony tissue. Covering the brain is the skull or cranium, which is made up of eight bones, the frontal, the occipital, two parietal, two temporal, the sphenoid, and the ethmoid, while the bones of the face are fourteen in number, two nasal, two superior maxillary, two lachrymal, two malar, two palate, two inferior turbinated, the vomer, and the inferior maxillary. ”

“ For the essential part of the sense organ, in this case, is the membranous labyrinth, a bag of complicated form, which lies buried in the depths of the floor of the skull, and is surrounded by dense and solid bone. ”

“ All the lobes, as they dip inward, are subdivided by numerous denotations, which afford points of attachment to the mantle of the animal; thus each lobe is flanked by a series of accessory lobes, and these again are provided with further symmetrical denotations, the extremities of which produce all the beautiful appearances of complicated foliage, which prevail through the family of Ammonites, and of which we have a striking example on the surface of Pl. ”

“ If we pursue our researches into the interior of this animal, we find within the framework of the skeleton a great cavity, or rather, I should say, two great cavities,—one cavity beginning in the skull and running through the neck-bones, along the spine, and ending in the tail, containing the brain and the spinal marrow, which are extremely important organs. ”

“ A spinal column may be a uniform solid axis, or a highly diversified segmented axis. A limb may be an arm, or a leg, a wing, or a paddle. In every case the anatomist recognizes a specific type. He assigns the uniformities to the uniformity of the substance thus variously shaped, under a history which has been similar; the diversities he assigns to the various conditions under which the processes of growth have been determined. He never expects a muscular tissue to develop into a skeleton, a nervous tissue into a gland, an osseous tissue into a sensory organ. ”

“ Single specimens of the segments show that the axial lobe was nearly as wide as the pleural lobes, that it was moderately convex, and that a small node occurs at the center of each segment near the posterior margin; also that on the outer side of each segment a rounded transverse node is outlined from the main body of the segment by a slightly oblique transverse furrow; pleural lobes nearly flat out to the geniculation where they curve gently downward ”

“ We always could say: the lobes are highly independent in action, but they are firmly married by this wonderful ligament—if it is a ligament. Even this comfort is now taken from us. Science has just rudely snatched away the corpus callosum. ‘The two lobes can get along without it,’ grunts science. ‘People have lived for years with no impairment of their brain power with a totally shrivelled corpus callosum.’ It is hard to keep pace with these cynicisms of science. ”

“ These masses of grey matter, taken together, are the basal nuclei of the brain. Internal to the lenticular nucleus, and between it and the caudate nucleus in front and the thalamus behind, is the internal capsule, through which run most of the fibres connecting the cerebral cortex with the crus cerebri. The capsule adapts itself to the contour of the lenticular nucleus and has an anterior limb, a bend or genu, and a posterior limb. ”

“ The natural body is formed from the different degrees of matter. The lower parts of the body, the skin, bones, and flesh are composed of the lowest discrete degree of matter, the earthy and aerial substances. The nerve system employs in addition the still higher discrete degree of ether in which is electricity: the ethereal matter furnishes the medium through which the muscles are operated from the mind. The purest matter in the brain constituting the Limbus, is from the purest aura, a still higher discrete degree. ”