24 REGENERATION 



morphosis." 1 Under this heading we may distinguish two cases, in one 

 of which the entire lost part is at once, or later, replaced holomorpho- 

 sis ; in the other the new part is less than the part removed mero- 

 morphosis. When the new part is different from the part removed the 

 process hasbeen called by Loeb " heteromorphosis," but there are at least 

 two different kinds of processes that are covered by this definition. 

 In one case the new part is not only different from the part removed, 

 but is also an organ that belongs to a different part of the body (or it 



FlG. 12. After Herbst. Diagram showing brain, eye, and " heteromorphic " antenna (in place 

 of eye of one side) of palasmon. The animal had lived in a dark aquarium for five months. 



may be unlike any organ of the body). This we may call " neomor- 

 phosis." As an illustration of this process may be cited the develop- 

 ment of an antenna, when the eye of a crab or of a prawn is cut off 

 near the base (Fig. 12); and as an example of an organ different in 

 kind from any organ of the same animal, may be cited the case of 

 Atyo'ida potimirum, in which the new leg is unlike any other leg on 

 the body. The name " heteromorphosis " can be retained for those 

 cases in which the new part is the mirror figure of the part from 

 which it arises, or more generally stated, where the new part has 



1 This term is used by Driesch in his Analytische Theorie, 



