100 GLANDS IN HEALTH AND DISEASE 



tissue in the desired place, or by first carefully 

 connecting the engrafted with the main tissue by 

 stitching suitable blood vessels together. In the 

 first case general circulation in the engrafted tissue 

 is for a time delayed; in the second, it is immedi- 

 ately set up. The first method has been exten- 

 sively used in replacing small portions of skin in 

 burns. It has even been employed, and with suc- 

 cess, to interchange the ovaries in hens, and to re- 

 place the thyroid and parathyroid. The second 

 method, more difficult to execute, has the advantage 

 in that the transplanted tissue may be of much 

 larger size. By this method the kidney, the spleen, 

 and even a limb have been transferred from one 

 dog to another ; and segments of arteries that have 

 been kept in cold storage, or preserved in formalde- 

 hyde, have successfully replaced portions that had 

 been removed from their positions in the body. 



It should be pointed out that, as a rule, trans- 

 plantation is successful only if tissues of the same 

 species are used, though experiments have shown 

 that the arteries of a dog can be transplanted to a 

 cat; and that further, much of the work recorded 

 has been done on animals rather than on human 

 beings. In the hands of Carrel and other famous 

 surgeons active in the late war, the art of grafting 

 has made long strides. The French doctors have 

 proved themselves particularly skillful in the art. 



The famous Siamese twins illustrate a perfect 



