Eugène Dupuy

“ It is well known that a system of nerves exists in all animals which have a circulation, and which apparently has no other functions but to control the blood-vessels, to regulate the flow of the blood through them. ”

“ The muscles of the legs are contracted stiff, those of the chest are thoroughly so; very soon all the muscles are the seat of convulsions. Respiration, which was in no little degree impeded during the time that the muscles of the chest were rigid, now becomes more frequent but very irregular. After a while the animal recovers, and remains in a state of stupidity for some time. It is not unfrequent to observe in these epileptic seizures fits of insanity—if I may use such a term when speaking of Guinea-pigs, but that word only will make my meaning understood. ”

“ If a puncture be made into that portion of the upper part of the spinal cord which anatomists call the restiform body, in Guinea-pigs, it will be seen that the animal presents at once an increased vascularity of the ear on the corresponding side; the ear becomes gorged with blood, chiefly toward the periphery: sometimes in a very short time, indeed, that portion of the ear falls off, destroyed by dry gangrene. ”

“ I have sometimes noticed that if a male or a female belonging to any one of the successive generations is allowed to breed with another healthy animal, very generally some of the young present the same hereditary peculiarities. ”

“ When the sciatic nerve has been cut or torn away, the greater portion of the leg is paralyzed as to motion and sensation, which is natural enough, because the muscles can no longer obey the mandates of the will, being deprived of the nerves which carry them, and also the centres no longer receive impressions which formerly came from those muscles and the skin covering them, because the nerves which carry the impressions have been destroyed. ”

“ It will be seen that lesions which affect not only nutrition of parts, but also the higher functions of the nervous system, can be developed by hereditary tendencies, when artificially provoked, through those nerves which minister to organic functions—belonging to the so-called sympathetic system. ”

“ Now, all these phenomena may disappear after a while, except a few. The eye always remains smaller, although the blood-supply of the eyelid is more regulated; the pupil remains a little contracted, and the secretion of tears continues, and also the nictitant membrane remains in a congested state. No matter how long the animal lives, that state of the eye persists, and when the animal dies, or is sacrificed, it is seen that this eyeball is smaller than its fellow. ”

“ Galton has committed a grave error, in his very remarkable paper on "Heredity" published not very long ago, in which he stated that the Guinea-pigs which had epilepsy without alteration induced in their nervous system may have acquired the disease by imitation, just as, it is well known, is too frequently the case in the human species.
First, all the children or adults who happen to live with epileptic patients and witness their paroxysms do not develop epilepsy; only a very few do so. This fact would show, therefore, that those who do develop epilepsy have some tendency ”

“ Brown-Séquard found that when the spinal cord of a Guinea-pig is pricked, or a portion of it is destroyed, or one of the sciatic nerves—that is, one of the largest nerves of the hind-leg—is either sectioned or torn off from the spinal cord, the animal in the course of a few weeks develops the epileptic malady. ”

“ The ear also becomes hotter, and, if the animal is white, we can see that the ear which before was white, with some blood-vessels stretching across, is now become red, and presents a very rich network of capillaries, which have become apparent, being of enlarged calibre. ”

“ But in the young which have inherited the taint no such explanation obtains. Their nerves have not been operated upon, not torn nor cut. How are we to explain their cure, and this fact, which is, as I have said, the peculiar feature of this heredity, that the cure in the parent which has so characteristic stages should have exactly the same stages in the young as to circumstances and time? ”

“ The fits become simple convulsions, then mere twitchings, and lastly the animal can no longer be distinguished from another healthy one but by the fact that it has only one toe at one of its hind-legs, when the operation has been performed on the sciatic nerve; and nothing whatever remains when the origin of the disease was a prick in the spinal cord. ”

“ When the spinal cord has been operated upon, sometimes the feeling of pain is found lacking to a slight degree on the opposite side, and exaggerated below the point of the body at which the wound has been made ”

“ If, now, such an animal were allowed to breed with another—whether operated upon in the same manner or not—it would be seen that young which are born, apparently perfectly healthy, present a few days after birth all the phenomena observed in their changed parent or parents. ”

“ I have had occasion to observe only a very few, and I have been able to learn that the young are born healthy, apparently. Sometimes—almost always, in fact—they are born with only one toe in the hind-leg ”

“ The materials which compose animal bodies are endowed with properties which differ in every different tissue: for instance, we say that the muscular tissue has the property of contracting. These properties of tissues develop functions: for example, the contraction of the ciliary muscle permits correct vision; but it is evident that if the tissue does not keep up the process of nutrition, i. ”

“ They are very interesting, both physiologically and psychologically viewed. I shall occupy myself with the physiological aspects only, and their bearing on human pathology. Psychology is beyond my province. ”

“ At all events, it appears that the vocal cords are contracted, for not unfrequently the animal utters an inarticulated, unnatural, sharp cry, which may be taken for the passage of air through the obstructed larynx. ”

“ I have said that I would only deal with this subject of heredity in its physiological aspects, but I cannot refrain from recalling to the attention of the reader that such facts in the human species need to be studied by psychological physicians, because they occur in insane patients, as is well known. ”

“ It is seen that their eyeballs increase in size and protrude from their sockets, their ears after a few days become diseased, just like those of the parents, the subjects of experimentation, and drop off, eaten by dry gangrene. ”

“ But if, now, this separated end of the nerve is irritated, the reverse phenomena are seen: the blood-vessel contracts, its calibre diminishes. When small arteries are experimented upon, the calibre becomes so small that blood-corpuscles no longer succeed in passing through it. So that it becomes evident that that nervous system has a great function to perform with regard to the nutrition of all the parts, or rather of every organ in the body, including, of course, the central, i. ”