GRAFTING 403 



it persists and the more likely is the graft to grow. 

 Thus transplanted fragments of perichondrium and per- 

 iosteum not infrequently remain and produce new cartil- 

 age and new bone. The formation of new bone by the 

 periosteum can only be effected, however, when the cells 

 have some bony tissue to work upon, so that if it is 

 desired to produce bony formation by transplanted per- 

 iosteum, it is necessary to add fragments of bone, pref- 

 erably fragments to which the periosteum is already 

 attached. 



Morris successfully grafted a part of an ovary from 

 one woman upon the uterine wall of another whose 

 ovaries, being diseased, were removed. The patient 

 subsequently menstruated, showing that the graft not 

 only lived, but performed a vicarious function. 



In surgical skin grafting it is not unusual for one 

 normal person to donate some of his skin to supply an- 

 other with needed integument. Just as in autoplastic 

 grafting, such grafts usually take, though whether the 

 newly acquired skin persists or is gradually absorbed 

 and replaced by skin of the patient's own development 

 is a question, for interesting changes take place in the 

 graft. 



Thus when the skin of a negro is grafted upon a white 

 person, it remains for a time unchanged, then either 

 loses its pigment or is thrown off by a new white skin 

 that develops beneath it. Loeb found that when skin 

 from a colored guinea-pig was transplanted to an albino, 

 it eventually lost its color and, vice versa, when the 

 skin of an albino was transplanted to a colored animal, 

 it became pigmented in the course of time. Here, 

 again, we cannot be certain that the transplanted skin 

 persists. It may be imperceptibly destroyed and 

 replaced by the gradual growth of the normal skin of the 

 animal. 



The transplantation of embryonal tissues is not differ- 

 ent from that of adult tissues. Fischer transplanted the 

 leg of an embryo bird to the comb of a cock or a hen, and 



