Barrel organ

“ In consequence of its not making the tissues shrink, it does not squeeze the blood out of the vessels and where the organ has been congested before death, we may, by using Müller’s fluid, preserve a natural injection of the capillaries.
3. There is comparatively little danger of over-hardening the tissue and rendering it brittle.
4. Sections of organs hardened in Müller’s fluid are usually firm and easy to manipulate. They do not tend to curl up or adhere to one another as much as those hardened in spirit. ”

“ The blood vascular system consists of the heart, the arteries, the veins, and the capillaries.
The heart is the central, propelling organ. The arteries form a series of efferent tubules, which, by branching, constantly increase in number and decrease in caliber, and which serve to carry the blood from the heart to the tissues. The capillaries are extensions from these latter tubules into which the arteries empty, and through the walls of which the interchange of elements between the blood and the other tissues takes place. ”

“ The lungs appeared in a normal state. The stomach contained about forty grammes of a thick, yellow, slimy liquid; and here and there parts of the mucous membrane were inflamed. The œsophagus, the intestines, the liver, the spleen, and the kidneys, were in a normal state. The epithelium was easily detached from the tongue; the base of this organ was red and slightly excoriated. The brain was more injected than its enveloping membranes; the pons varolii was the same as in the second experiment.
Fourth Experiment.—I applied on the eye of a dog of moderate size one drop of nicotine ”

“ As every organ is nourished, and as the mechanism of nutrition is uniform, it follows that these two systems belong to all the organs. After them the cellular system is the most generally found. Where there are no blood vessels, it is sometimes met with, and it always exists where these vessels are. Next to this, the arteries and veins are spread to the greatest number of parts. Oftentimes no nerve is discoverable, where they penetrate, as in the aponeuroses, the fibrous membranes, &c. ”

“ To each the blood is carried by a branch of the dorsal vessel, which traverses the organ to its extremity, and, looping, carries the aerated fluid to the ventral vessel. Vascular loops pass between the two branches in the branchiae, and only very thin cuticular tissues covered with cilia intervene between the water and the blood, so that due oxygenation occurs. ”

“ The substance of the spinal cord is seldom changed, either in vascularity or in consistence: the morbid changes which this organ undergoes have hitherto been observed only in the membrane that invests it, which, as has been just stated, is not only highly vascular, but likewise contains a much larger quantity of fluid than natural. ”

“ We have seen, then, fine injections pour out upon the serous membranes, upon the pericardium, the pleura, the peritoneum, &c. transude upon the mucous surfaces, even upon the skin. We have seen them flow through the ureters, the pancreatic, biliary, salivary ducts, &c. Haller, in the article upon each organ, has not failed to relate examples of this sort, which prove the communication of the arteries with all the other vessels, by means of the capillary net-work. What anatomist has not sometimes made even coarse injections return by the veins? ”

“ The walls of the organ are composed almost entirely of a soft, tender parenchyma, formed, for the most part, of vascular ramifications, the trunks of which, three or four in number, communicate with the interior of the branchial heart, through the peduncle. The walls of these trunks and of the peduncle are composed of stout, tough membrane. The cavity of the appendage does not communicate with that of the heart, but opens, as we have seen, externally, or into the chamber within which the organ is placed, so that the fluid surrounding it will bathe its inner as well as its outer surface. ”

“ When the instrument is in use, the kidney lies between two delicate, exceedingly flexible membranes, which apply themselves closely to its surface and to the surface of the structures entering the hilus of the organ, and each of these membranes forms with each of the symmetrical halves of the box a chamber which is filled with oil and which communicates by a relatively wide flexible tube with the recording instrument. ”

“ The excretory, the lungs, skin, and kidneys, by means of which those waste matters pass out of the body. As far as the subject of clothes is concerned, we have to deal chiefly with the circulatory system in its relation to the skin.
The circulation of the blood is carried on by means of the heart, arteries, and veins.
The heart is a very powerful muscle, which acts as a kind of pumping machine; it is divided down the middle, by a muscular partition, into two parts, called the right and the left side, and no blood can pass from the one side into the other. ”

“ The essential part of each luminous organ is always a collection of gland cells, usually disposed so as to form the lining of a series of radially arranged gland-tubules in the deeper part of the organ, which also contains ganglion cells, and is supplied with nerves from contiguous spinal or cranial nerves. ”

“ The notochord, nerve-tube, muscles, etc., are withdrawn into the body, where they break down and are absorbed by phagocytes. The posterior part of the nerve cord and its anterior end with the large sense-organs disappear, and the middle part or trunk-ganglion is reduced to form the relatively small ganglion of the adult, underneath which the hypophysial tube gives rise to the neural gland. While the locomotory, nervous and sensory organs are thus disappearing, or being reduced, the alimentary canal and reproductive viscera are growing largely. ”

“ The red blood corpuscles of the rabbit, it may be added, are nucleated for a considerable portion of embryonic life. Larger vessels and the heart are burrowed, as it were, out of masses of mesoblast cells. The course of the blood in the embryo is by the veins to the right auricle, thence through the imperfection of the auricular septum already alluded to, into the left auricle. Then the left ventricle, aortic arches (for the future pulmonary artery is in communication by a part presently blocked, the ductus arterious, with the systemic aorta) , arteries, capillaries, veins. ”

“ And then it seems only reasonable to think that the blood in its circuit passes more slowly through the kidneys than through the substance of the heart; more swiftly through the liver than through the kidneys; through the spleen more quickly than through the lungs, and through the lungs more speedily than through any of the other viscera or the muscles, in proportion always to the denseness or sponginess of the tissue of each. ”

“ One system supplies the kidney substance with nourishment in the form of nutrient blood; the second system supplies the glomerules with what may be considered functional blood (Gadow) . The second system of arteries branches into the small arteria interlobularis, which pass between the lobules of the kidneys where they give off side branches which penetrate the cortical portion of the lobules and form the capillary plexus, the glomerule. ”

“ In the rabbit a vein is a vessel bringing blood towards the heart, while an artery is a vessel conducting it away. Veins are thin-walled, and therefore flabby, a conspicuous purple when full of blood, and when empty through bleeding and collapsed sometimes difficult to make out in dissection. They are formed by the union of lesser factors. The portal breaks up into lesser branches within the liver. Arteries have thick muscular and elastic walls, thick enough to prevent the blood showing through, and are therefore pale pink or white and keep their round shape. ”

“ The vascular system itself is quite peculiar, consisting of lacunae and channels destitute of endothelium, situated within the thickness of the basement-membrane of the body-wall, of the gut-wall and of the mesenteries. The blood, which is a non-corpuscular fluid, is propelled forwards by the contractile dorsal vessel and collected into the central blood-sinus; this lies over the stomochord, and is surrounded on three sides by a closed vesicle, with contractile walls, called the pericardium (Herzblase) . ”

“ If blood still will not flow, it may mean that there is a clot ahead of the drainage tube. Pump some fluid through the drainage tube into the vein, to see if the tube is open, then let the fluid drain out which usually will bring some blood. After you have tried all the methods, if blood still does not flow, it will indicate that the blood is either in a coagulated condition, or there is not very much blood in that particular vein, which in this case is the femoral. The blood may be more in the dependent parts of the body. ”

“ A very interesting observation which I made long ago, but to which I have not before directed attention in this point of view, shows that an extreme degree of adhesiveness of the red discs may exist within a blood-vessel the walls of which are in perfect health with reference to coagulation. If a horse's jugular vein, obtained in the manner I have described, is suspended vertically, the blood in it remains fluid for an indefinite period, hut the red corpuscles soon fall from the upper parts of the fluid, leaving a huffy layer of plasma, readily seen through the translucent wall of the vessel. ”

“ The body becomes much longer, and is compressed at the sides, the head-end being broadened in a sort of triangle. Two rudimentary sense-organs are developed in it. Inside we find the first blood-vessels, an upper or dorsal vessel, corresponding to the aorta, between the gut and the dorsal cord, and a lower or ventral vessel, corresponding to the subintestinal vein, at the lower border of the gut. Now, the gills or respiratory organs also are formed at the fore-end of the alimentary canal. ”

“ The serous membranes of the brain, thorax, and abdomen are in many cases found reddened with effusions, more or less considerable, into the ventricles of the brain and the pleural, pericardial, and peritoneal cavities from the sudden inflow of blood from the surface, caused by the local injuries.
When the body has been badly charred or incinerated the skeleton usually remains, and it is possible to determine the age from the size and development of the bones and the sex from the shape of the bones of the pelvis. Careful search should be made for special articles of identity. ”

“ The resemblance is particularly strong if we compare the lower layer with the Hornblatt of the upper layer—both consist of epithelial tissue, and of its derivative, glandular tissue, and form neither vessels nor nerves. The middle layer, on the contrary, forms nerves and muscles, vessels and connective tissue, and little or no epithelium. It does not form all the blood-vessels without exception (and so cannot be called the vessel-layer) , for the blood-vessels of the central nervous system are in all probability formed from the upper layer. ”

“ For example, in the case of the spleen, the capsule, trabeculæ, pulp, stroma, follicles and vessels should be examined; in the liver, the capsule, trabeculæ, liver-acini, blood-vessels and bile-ducts; in the kidneys, capsules, cortical surface, cortex, labyrinths and medullary rays, glomeruli, columns of Bertini, medullary pyramids, vessels, pelvis and beginning of ureter. When the organs are thus systematically examined there is but little chance that anything visible to the naked eye has been overlooked. ”

“ Intracardiac injection, or aspiration of the heart to secure blood, requires considerable practice to be successful without causing the death of the animal at once through internal hemorrhage. In subdural injections into the cranial cavity it is necessary to trephine the skull first, while such injections into the spinal canal may be accomplished between the vertebra with needles longer and stronger than the usual hypodermic needle. ”

“ The hands are often clenched, and the soles of the feet arched and inverted. The membranes of the brain and of the upper part of the spinal cord are congested; and there is often considerable serous effusions under the spinal arachnoid. The lungs are generally loaded with dark fluid blood. ”

“ The skeletal muscles and the muscular walls of the viscera at each contraction express the blood within them, and materially influence the circulation. The whole muscular system, as well as the heart, must therefore be regarded as a pump to the vascular system. The capillary wall is composed 'of a single layer of flattened cells, separating the blood within from the tissues without. ”

“ Parts of vascular systems appear to have arisen in some cases by a canalization of cells.
The blood systems may either be closed or communicate with the body cavity. In cases where the primitive body cavity is atrophied or partially broken up into separate compartments (Insecta, Mollusca, Discophora, etc.) a free communication between the vascular system and the body cavity is usually present ”

“ The tissue with which they are continuous, which is exactly equivalent to the tissue from which the neural arches originate, is not truly a part of the rib. In the tail, behind the anus and kidneys, the cardinal veins fuse to form an unpaired caudal vein below the aorta, and in this part a fresh series of processes originates on each side from the hæmal tissue adjoining the cartilaginous sheath of the notochord, and eventually, by the junction of the processes of the two sides, a canal which contains the aorta and caudal vein is formed below the notochord. ”