Transplanted Parts Soon Cease to Develop 123 



ment, accompanied either by no morphologic alterations 

 or by quite aspecific ones, depending upon whether the 

 portion cut away consisted of a formless fragment of 

 tissue, or of an organ whose proper form was already 

 indicated. We may mention, for example, Zahn's trans- 

 plantations of portions of cartilaginous or bony fetal 

 tissues to the lungs and kidneys of other individuals of 

 the same or different species, 85 or Fischer's transplanta- 

 tions of anterior and posterior extremities of chicken 

 embryos (especially of one incubated only eleven days) 

 to the comb or ruff of the cock. 86 



It is true that both, and especially Fischer, have 

 observed that in these extremities of chicken embryos, 

 ossification, which at the time of amputation had not 

 commenced at all or had scarcely commenced, was 

 initiated or continued in the transplanted extremities. 87 

 But this process of ossification can be considered only 

 as the mere accumulation, and consequent intensification, 

 of the effects of the specific vital activity which was 

 already at work before the amputation, and which 

 persists unaltered after the transplantation. 



Consequently we think that Roux is quite wrong 

 when, apropos of these experiments of Zahn, Fischer, 

 and others, he expresses himself as follows: "These 

 experiments have demonstrated that many isolated 

 embryonic parts can not only grow but even become 



"Zahn : Uber das Schicksal der in den Organismus implantierten 

 Gewebe. Virchows Archiv, Bd. 95. Drittes Heft, 5. March 1884; 

 especially e. g. P. 374375, 380, 381. 



"Fischer: Uber Transplantationen von organischem Material. 

 Deutsche Zeitschrift der Chirurgie, Bd. 17. Erstes, Zw., Dr. u. Viertes 

 Heft, 1882; especially e. g. P. 362363, 370371. 



"E. g. Zahn: Uber das Schicksal etc. P. 382ff. Fischer : Uber 

 Transplantationen etc. P. 370, 374. 



