647] AUTOPHOBIC TRAN8PLANTATI0X 549 



manufactured anew by the remaining body of the ani- 

 mal, such ' ' Eegeneration ' ' not being uncommon even in 

 whole extremities of amphibians and crayfish. But, un- 

 fortunately, in the warm-blooded vertebrates this faculty 

 is very limited, not extending much beyond the repair of 

 small pieces of tissue, and never including a whole organ 

 or appendage. It has therefore long been customary in 

 human medicine to try to replace lost parts by " trans- 

 plantation " of cornea, skin, muscle, bone, or even nerve 

 and blood vessel. Without regard to the composition of 

 the injured part, small pieces or larger portions have 

 been taken from the same or from another individual, 

 and again without special orientation have been grafted 

 upon the wound. All sorts of fastenings have been tried, 

 bandages, plaster, wires, ligatures, but mostly with poor 

 results. The same methods and many others have been 

 applied in experimental zoology, but only when embry- 

 onic stages which had not functioned before the operation 

 were used have good results been achieved. Neverthe- 

 less it has been demonstrated by A. Carrel that even 

 whole limbs and kidneys may be again healed back in 

 mammals and in the case of the latter again become func- 

 tionally active. But the tedious method of sewing every 

 sinew, blood vessel and nerve together seems to have pre- 

 vented till now the general application of this discovery. 

 Carrel's method, as also that of other surgeons, must be 

 compared to the third method of the engineer, when he 

 is soldering or fixing a broken piece on to another, trying 

 to repair the machine without taking it to pieces. Now 

 it is generally simpler to take out the injured piece of 

 a machine, by unscrewing or unsoldering or even by 

 striking it out of the whole by sheer force, so that its 

 connections give way at the points of least resistance, 

 and to replace it by a new one of exactly the same form, 

 than to try and fix the broken parts together again at 

 the point of breakage. Is there a possibility of applying 

 this fourth method of the engineer to the organism? One 

 will, perhaps, at first be inclined to doubt this proposi- 



