AUTOPHORIC TRANSPLANTATION, ITS THEORY 

 AND PRACTISE 



PEOFESSOR 'HA-NS PRZIBRAM 

 BioLOGiscHE Yersuchsanstalt der Akademie der 



WiSSENSCHAFTEN, ViENNA 



If a machine breaks down, the mechanical engineer has 

 four ways of repairing it. He may discard the broken 

 parts and reconstruct the whole on a smaller scale; he 

 may fabricate the missing part and fit it into its right 

 place again; he could also take a piece from another 

 machine of more or less similar type, as long as an ex- 

 change is made possible by the material of the parts, 

 soldering the broken pieces together or fixing them by 

 screws, wires, etc.; or lastly he may simply exchange 

 the broken part for a whole one, first taking the former 

 out of the broken machine at the points where it was 

 joined, and refitting the new part, taken in like manner 

 out of a similar machine by the same means, in the place 

 of the first. An organism is often just as badly in want 

 of repair as a machine of human fabric. In comparing 

 the two I do not wish to enter here into the controversy 

 of Mechanism versus Vitalism. No vitalist will deny 

 that the body of an animal, let us say of vertebrate or 

 arthropod type, is built up of various contrivances the 

 physicist calls machines, and that its functions are best 

 described in physical and chemical terms. It is not the 

 machinery of organized forms that he w^ould throw doubt 

 on, but the mechanical or chemical nature of its driver. 

 Now, when living machinery is broken or maimed, there 

 are the same four possibilities of repair stated above. 

 The organism may shed such parts as are now super- 

 fluous for its reduced size and reconstruct itself on the 

 basis of a proportionately diminished form, as in small 

 pieces of planarians, a process called " Morphallaxis," 

 by T. H. Morgan. Secondly, a missing part may be 

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