Rensselaer Union, Volume 7, Number 47, Rensselaer, Jasper County, 12 August 1875 — Reproduction of Organisms. [ARTICLE]

Reproduction of Organisms.

The epidermis, or outer skin, grows with the greatest facility, just as the hair and nails; it is, indeed, the same tissue. The crystallizing lens of the eye, which somewhat resembles the substance of the epidermis, is also reproduced when it is taken away. Many experiments made<on dogs and rabbits proved that this bi-con-vex lens, which is one of the principal organs of sight, is perfected afresh in a few months.

Besides this skin, there are the nerves, the restoration of which was unknown until the end of the last ceitury, when Monro and some others drew up a complete theory. In the sciatic nerve, for instance, it is sometimes necessary to cutout about the third of an inch. The aids soon show an alteration; then, in about six weeks or two months, a gray lump appears on one extremity, which directs its course toward the opposite one and reunites with it. This is composed of nervous tubes, more slender than the original ones; but by degrees they grow in size, become whiter, the fibers are more perfect, and, after an interval of four to six months, there is a cord of nerves newly formed. This process will go on even when two inches have been excised. As the matter is repaired, the progressive re-establish-ment of the sensitive functions can be seen, whether of motion or of feeling. The cartilage, which is perhaps Better known under the name of gristle, wasconsidered for a long time as incapable of renovation, but in 1867 this was found to be a mistake. The cartilaginous tissue of dogs and rabbits was divided, and at the end of two months there was a complete restoration. It is also found that the thinner muscular tissues, which perform involuntary movements in the interior of the body, possess the same power. One point only remained to be proved—whether muscular fibers could restore, by means of similar fibers, their loss of substance, This w«s tried on some guinea-pigs; the muffles were cut, and after a few months were found to be complete agaip. Thus all the tissues of the animal frame van be restored to the adult, and by a precisely similar plan of development as A the young. _ The operation of Rafting in the vegetable kingdom is i&U known; living fragments are attained to a perfect tree. But the grafted portion never becomes an integral pj*t of that to which it has been transported; it rather develops as a parasite, like the mistletoe on the oak, ana remains physiologically distinct. This, however, .is not the case with animals. When a piece taken from another part of the same individual, or from a different subject, is grafted it becomes a perfect portion ana gives the same life. The cells of the ehoroid coat of the eye maybe transplanted, and preserve their vitality in their new home. The transfusion of blood is nothing but the introduction of red globules borrowed from one organism and transferred to another. This succeeds even if the blood passes into an individual of quite a different class, as, for instance, from a mammal into the vessels of a frog. The globules will be found after some time living, and easily recognizable as those of a superioranimal. The spurs of one cock have been grafted into the comb of another, and teeth of mammals have also been transplanted. From these facts surgeons took up the idea of grafting bones in the place of those that had decayed, and several attempts seemed to favor the plan; but now it is acknowledged that a graft of either the periosteum or the marrow has a strong tendency to be reabsorbed or to disappear after a time on account of the unfavorable conditions in which it finds itself, or for want of nutrition.

More success has attended the grafting of teeth; but this is not yet quite established. The teeth spring from a little bag or follicle, in which is the organ of ivory, and that for the production’ of enamel. When an entire follicle was taken from a puppy and grafted into an adult dog the germ was regularly developed to the production of a complete tooth. The enamel when grafted alone perished, while the organ of ivory produced an ivory tooth. These interesting researches led to the hope that teeth may some day be thus restored, seeing that an entire organ with complete structure is more likely, to grow than when it i« only a fragment, transplanted and isolated, like a piece of bone. The grafting of the epidermis has been accomplished by many of the celebrated surgeons. After an operation, a bum, or a bruise, the destroyed skin is but slowly restored, and often with difficulty. Thus the ideas arose of taking a piece of healthy skin from the same or another person, and laying it on the wound. It was found to require the utmost delicacy on the part of the surgeon; and, instead of covering the whole with one piece, very small bits were applied each day following the progress of healing, and replacing those morsels that did not adhere. In about twenty-four hours the grafting was accomplished, and the wound was not, as usual, a contracted scar. Such are some of the efforts of physiology. The working out is difficult and tedious; but, with skill and patience, the labors of the present time may bear future and valuable fruit Chambers' Journal.

The Reading (Pa.) Eagle gives to account of some rattlesnake-hunters who search for these reptiles in the Blue Mountains. The hunters go in pairs always, so that if one is bitten the other can come to his relief. Their boots are very heavy and thick, and the soles are covered with rubber, so that they can move noiselessly and with safety across slippery and rocky places. At noon is the best time to catch snakes, for then is the time that they stre.tch themselves across the rocks to sun themselves. A rattlesnake very rarely closes its eyes and Its power of scenting is very great It moves very slowly and bites only when provoked. Tne men carry iron hofcks with a prong at the end. Others an iron with a curve at the end of it, which they press down over the snake’s head on the rock. They then take a pair of wooden pincers, nip the reptile in the jaws, holding them very tight, and thus raise them and put them into a box with a wire screen over the top of it. That is the way the snakes are captured . alive. The men kill them for pleasure and the skins are preserved as trophies, just as the Indiahs value the scalps of their victims.