DEGENERATION. 29 



tion " to so act on the structure of an organism as 

 to produce one of three results, namely these ; to keep 

 it in statu quo; to increase the complexity of its 

 structure ; or lastly, to diminish the complexity of its 

 structure. We have as possibilities either BALANCE, 

 or Elaboration, or Degeneration. 



Owing, as it seems, to the predisposing influence 

 of the systems of classification in ascending series 

 proceeding steadily upwards from the '' lower " or 

 simplest forms to the "higher" or more complex 

 forms, — systems which were prevalent before the 

 doctrine of transformism had taken firm root in the 

 minds of naturalists, there has been up to the present 

 day an endeavour to explain every existing form of 

 life on the hypothesis that it has been maintained 

 for long ages in a state of Balance ; or else on 

 the hypothesis that it has been Elaborated, and is 

 an advance, an improvement, upon its ancestors. 

 Only one naturalist — Dr. Dohrn, of Naples — has put 

 forward the hypothesis of Degeneration as capable of 

 wide application to the explanation of existing forms 

 of life ;^ and his arguments in favour of a general 



^ Der Ursprung der Wirbelthiere und das Princip des Functions- 

 wechsels. Leipzig, 1875. 



