The skin of the frog has successfully been implanted upon granulating surfaces by Baratoux and Dobousquet-Laborderie. They observed that the peculiar pigmented mottling of the skin disappeared about the tenth day, and that the grafts gradually took on the appearance of human skin thereafter.
The best results in this method are obtained with the skin taken from the back of the frog in preference to that of the belly or legs. This skin is cut into pieces about one fourth inch square, which are placed upon the granulating surface in rows, each graft being separate from its neighbor by a space of half an inch.
At the end of forty-eight hours the plaques of skin will have adhered to the granulating surface. At the end of five days they lose their original color and send out cells of epithelium to each neighboring square.
The dressing to be applied over the flaps should consist of borated vaselin, one dram to the ounce, which is smeared upon strips of sterile gauze, over which loose gauze is placed, held in place by a roller bandage.
The skin, once organized, is very thin, as a rule, and requires more or less care for some time after.
General Remarks
The skin of the grafted area will always present a different appearance from that of the healthy skin, both as to color, which is always paler, and in texture. The grafted portion is usually slightly elevated above the healthy skin, giving it an edematous look.
It has been found that skin grafts taken from the negro take more successfully than those from the white race. White skin flaps placed upon the negro do not meet with much success. In this event, however, the newly grafted skin soon takes on the color peculiar to the negro and vice versa (Thiersch).
The investigations of Karg seem to show that the pigmentation of skin is not secreted in the rete, but is carried to it by wandering cells arising from the deeper layer. Von Altmann has discovered certain cell granules, termed by him bioblasts, which he believes are responsible for the production of the pigmentary deposits under peculiar influences of the blood.