Dorsal

“ A typical vertebra consists of a middle portion, the centrum, a dorsal portion, the dorsal or neural arch, which surrounds the spinal cord, and a ventral portion, the ventral or haemal arch, which similarly encloses a space. ”

“ Make a man lean forwards, with his arms folded across the chest; this will make prominent the spines of the vertebræ. The lower border of the trapezius will guide you to the spine of the twelfth dorsal vertebra. ”

“ The animal or nervo-osseous system must separate from the vegetative system of bones, and be placed upon the side exposed to the light. The side of the inferior animal that is exposed to the light, or averted from the earth, is the upper surface, dorsal region or back. ”

“ The spine or back-bone should be straight and long, rather loosely hung, or open along the middle part, the result of the distance between the dorsal vertebræ, which sometimes causes a slight depression, or sway back. ”

“ The dorsal spines of the vertebrae are connected with a set of ossified ligaments binding the whole dorso-lumbar region into a rigid mass—another peculiarity in which the structure is strikingly like that of birds. ”

“ Two or three of the anterior dorsal vertebrae have very long slender spinous processes which in the living animal project beyond the general level of the skin forming distinct conical prominences, covered only by an exceedingly thin and naked integument. ”

“ Fig. 265. Vertical longitudinal section through part of the trunk of a young Scyllium embryo.
com. commissure uniting the dorsal ends of the posterior nerve-roots; pr. ganglia of posterior roots; ar. anterior roots; st. segmental tubes; sd. segmental duct; g.e. epithelium lining the body cavity in the region of the future germinal ridge.
The attachment to the dorsal summit is not permanent, but [Pg 450] before describing the further fate of the nerve-rudiments it is necessary to say a few words as to the neural crest. ”

“ Nerves coloured red are the motor nerves to the branchial muscles. Nerves coloured blue are the internal sensory nerves to the diaphragms and the external sensory nerves to the sense-organs of the lateral line system. Br. cart., branchial cartilage; M. con. str., striated constrictor muscles; M. con. tub., tubular constrictor muscles; M. add., adductor muscle; D.A., dorsal aorta; V.A., ventral aorta; S., sense-organs on diaphragm; n. Lat., lateral line nerve ”

“ Although the ventral zone receives medullary fibers and itself produces nerve fibers, it sends, so far as yet observed, no fiber into the dorsal zone, but all the fibers which leave the ventral zone form nerve roots and leave the nervous system altogether. ”

“ There has been absolutely no ingenuity on my part; all I have done is to compare organs and their nerve-supply, as they actually exist in the two groups of animals, on the supposition that there has been no turning over on to the back, no reversal of dorsal and ventral surfaces. The comparison is there for all to read; it is all so simple, so self-evident that, given the one clue, the only ingenuity required is on the part of those who fail to see it. ”

“ Coloration.—The dorsal ground color is tan or straw; the dorsal pattern consists basically of dark middorsal blotches and dark lateral intercalary spots. Number of blotches, color of blotches posteriorly, width of pale interspaces between anterior blotches, and color of lateral intercalary spots vary considerably geographically. In some populations (lineaticollis and gibsoni) the anterior blotches are divided medially forming either a pair of dark stripes on the anterior part of the body or a series of paired spots. ”

“ In many reptiles, however, perhaps in part because of the closer articulation of the vertebrae, the head has migrated backward to articulate with a facet or process on the anterior end of the centrum, the parapophysis, and there it has remained in the cervical vertebrae of most reptiles, and in the dorsal vertebrae of the Squamata and their allies. ”

“ Brilliancy of coloration is most conspicuous in the Teleostei: in nearly all other Fishes the colours are more uniform, usually sober and often sombre, with no more variety than is afforded by the presence of dark spots or bands on a lighter ground, or vice versâ, or by the lighter colour of the ventral as compared with the dorsal surface. ”

“ The application of the above criteria to specimens from Michoacán has not resulted in the recognition of two species. The majority of the specimens have the supraorbital semicircles separated by at least one small scale; the head scales, with the exception of those on the snout in a few individuals, are smooth; the dorsal scales are only slightly smaller than the ventrals. In other characters of scutellation the specimens are highly variable. ”

“ Praecaudal vertebrae with transverse processes behind which the ribs are attached .......... 1. Carangidae.
Praecaudal vertebrae without well-developed parapophyses, ribs and epipleurals inserted close together on the centra .......... 2. Rhachicentridae.
II. Praemaxillaries not protractile; scales usually small or absent; body more or less elongate; dorsal fin elongate, single or divided, without free spines; no free anal spines. ”

“ The cervical region is that in front of the shoulder-girdle, the dorsal that between the shoulder and hip girdles, the sacral that which supports the hip girdle, and the caudal that of the tail.
We may hardly venture to guess as to the primitive number of vertebrae in reptiles. We are quite sure that there has been an increase in number in some, a decrease in others. The land temnospondylous amphibians that we know have but one real cervical vertebra, the so-called atlas, twenty-two to twenty-five dorsals, one or two sacrals, and a short or moderately long tail. ”

“ Comparison of specimens from the northern part of the Mexican Plateau (Chihuahua, Coahuila, and Durango—5 specimens) , the central part of the plateau (Aguascalientes, San Luis Potosí, and Zacatecas—13 specimens) , the southern part of the plateau (Guanajuato, Jalisco, México, and Michoacán—18 specimens) , and Puebla and southern Veracruz (12 specimens) shows the average number of ventrals for these samples to be, respectively, 221.6, 216.7, 221.3, and 220.0. The average number of dorsal body-blotches for the same samples are, respectively, 36.6, 37.7, 38.4, and 34.6. ”

“ The head is the treasure-vault of all our thoughts, emotions, sensations, and pas­sions; the thorax contains the heart and lungs; the abdomen all the digestive and secretive organs; and even the orifices are all mysteriously furnished. ”

“ Every muscle, every point on the skin, the eyes, the ears, the nose, the tongue, every several organ which we possess, has its own special spot on the surface of the brain, somewhere above or behind the ear. Each half of the body is charted on one side of the brain, a spot in one for each spot in the other. ”

“ I need only premise that what we call the nervous system in one of the higher animals consists of a central apparatus, composed of the brain, which is lodged in the skull, and of a cord proceeding from it, which is termed the spinal marrow, and which is lodged in the vertebral column or spine, and that then from these soft white masses—for such they are—there proceed cords which are termed nerves, some of which nerves end in the muscle, while others end in the organs of sensation. ”

“ Lying prostrate, with flaccid limbs, with head sunk back on the limp neck, motionless and still, at first sight, it seems quite dead and gone. But a gentle heaving of the body, a rise and a fall every few seconds, tells you that it still breathes; and a finger placed on the chest may feel the quick throb of the still beating heart. ”

“ When any physician, doctor, or amulet-maker puts his fingers upon the top of the head, upon the occiput, upon the hands, upon the chest, upon the arms, upon the legs, he communicates (?) with the heart, for its vessels extend to every limb, wherefore it is called the starting-point of every limb. ”

“ This movement of the whole limb is what we think of when the joint's nerves are excited in that way; and its place is so much more important than the joint's place that our sense of the latter is taken up, so to speak, into our perception of the former, and the sensation of the movement seems to diffuse itself into our very fingers and toes. But by abstracting our attention from the suggestion of the entire extremity we can perfectly well perceive the same sensation as if it were concentrated in one spot. ”

“ Although the organ called the brain is located in the head, and although that called the heart is in the abdomen, yet some sense of control over bodily motions curiously exists separately in the ganglions of different parts of the body. ”

“ The head of the animal, then, seems necessarily to be just as we find it, the seat of the special senses and of the brain; while the relative location of these sense-organs and of the mouth, the position and elevation of the head, and the narrowness and flexibility of the neck, appear to be all necessary adaptations for the most complete protection of the whole organism. ”

“ And what is very remarkable is, that, in speaking of these movements which arise by a sensation being as it were reflected from the central apparatus into a limb—as, for example, when one's finger is pricked and the arm is suddenly drawn up, the motion of the sensory nerve travels to the spine and is again reflected down to the muscles of the arm—Descartes uses the very phrase that, we at this present time employ. ”

“ The hand, fixed to the end of a long articulated column of bones, and, through its skin-covering, particularly in the cavity, endowed with high sensibility, raises itself to the importance of an organ of feeling, which, moveable in all directions, [Pg 17] apprizes us of the extent of matter, and of its physical qualities. ”

“ Thy wisdom is surely boundless, for I see that man must be wise to know all about the neck, for we find by a twist of neck, we may become blind, deaf, spasmodic, lose speech and memory, and all that is known as the joys of man. On that division of the body all action of arms, legs, chest and all muscles get their life [Pg 46] —power and motion. ”

“ We are told, and with perfect truth, that in man the occipital foramen--the aperture through which the brain is connected with the spinal cord--is so placed that the head is nearly in equilibrium when he stands upright. ”

“ If the spinal cord is divided in the middle of the back, for example, the skin of the feet may be cut, or pinched, or burned, or wetted with vitriol, without any sensation of touch, or of pain, arising in consciousness. ”

“ You know the head contains the brain, which is the king of the body, and commands all under him; and it depends on his being good or bad whether his subjects,—the legs, and arms, and body, and stomach, and our old friends the bowels, are in good order and happy, or not. Now, first of all, keep the head cool. Nature has given it a nightcap of her own in the hair, and it [47] is the best. ”

“ Dissimilar parts are those which we call organical, or instrumental, and they be inward or outward. The chiefest outward parts are situate forward or backward:—forward, the crown and foretop of the head, skull, face, forehead, temples, chin, eyes, ears, nose, &c., neck, breast, chest, upper and lower part of the belly, hypocondries, navel, groin, flank, &c.; backward, the hinder part of the head, back, shoulders, sides, loins, hipbones, os sacrum, buttocks, &c. ”

“ Within the body itself we have sense organs also, particularly in the joints and tendons and in the muscles. These give us the sensations which are the basis of our perception of motion, and of the position of the body and its members. ”

“ Every part of the body, with some few exceptions, is crowded with nerves and blood-vessels. The nerves all come from the brain or spinal cord—the vessels from the heart. So that every part of the body is governed by two centres, the heart, and the brain or spinal cord. ”

“ The anterior roots have not been so satisfactorily investigated as the posterior, but they grow out, possibly by several roots for each nerve, from the ventral corners of the spinal cord, and subsequently become attached to the posterior nerves. ”

“ We may see in our own bodies how each limb serves another. The feet bear the whole body, and the eyes lead the feet, and the hands prepare the sustenance. Soon will the head lie down, if the feet bear it not ”

“ Its peculiar characteristic is that the feet are no more active than any other part of the body; arms, shoulders, abdomen, head—all the parts and every muscle are set in motion, sometimes including even the eyes and the tongue. ”

“ The enormous hind quarters, the limbs and the loins, the broad pelvis, the thick spinal cord supplying abundant nervous energy to the swelling muscles, inserted in the ridged and keeled bones, all come into play, as a point d'appui for the Herculean effort. ”

“ In the human body they are found in great numbers in connection with the nerves of the hand, also in those of the foot. Why should they not be in the feet? Let us remember the rythmical structure of the human body, particularly the feet, and it becomes clear why they are there; the ecstatic dances of the enthusiasts and the not-sinking of somnambulists in water or their ability to use the soles of their feet as organs of perception and the ancient art of healing by the soles of the feet—all these facts explain the mystery. ”

“ The next thing is to think of the body as luminous, filled with light. The next thing is to concentrate on the base of the spine, not from the outside, but look down the spinal column inside to the base of the spine. ”

“ We are sensible of the position of our limbs; we know that the arms hang by the sides, or that they are raised and held out, although we touch nothing and see nothing. It must be a property internal to the frame by which we thus know the position of the members of our body; and what can it be but a [140] consciousness of the degree of action, and of the adjustment of the muscles? ”