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,®® 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.®® 
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.§” 
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. 374—375, 380, 381. 
*eRischer: Uber Transplantationen von organischem Material. 
Deutsche Zeitschrift der Chirurgie, Bd. 17. Erstes, Zw., Dr. u. Viertes 
Heft, 1882; especially e. g. P. 362—363, 370—371. 
°F, g. Zahn: Uber das Schicksal ete. P. 382ff.—Fischer: Uber 
Transplantationen etc. P. 370, 374. 
