NOTES. 



c. 



A VERY important form of degeneration, not 

 touched on in the text, is that exhibited in the 

 Mexican axolotl, where the larval 'form of a 

 Salamander develops generative organs, and is 

 arrested in its further progress to the adult parental 

 form. It is not possible to class this with the other 

 phenomena which I have enumerated as Degenera- 

 tion, since there is no modification of an adult 

 structure, but simple arrest, and retention of the 

 larval structure in all its completeness. I should call 

 the phenomenon exhibited by axolotl ** arrest " or 

 " super-larvation " rather than degeneration. 



The result of super-larvation is in so far similar 

 to that of those changes to which it is desirable to 

 restrict the term '* degeneration," that it may be 

 classed under " simplificative evolution " as opposed 

 to "elaborative evolution." That there is a very real 

 difference between super-larvation and degeneration 

 may best be seen by taking a case of each process 

 and instituting a comparison. Axolotl proceeds 



