

DEGENERATION. 71 



4. Reduced self-activity, and simultaneous with- 

 drawal from struggle for existence. Examples : Para- 

 sites, quiescent animals, compound animals. 



Distinction of degenerate forms from forms primi- 

 tively simple. Used up potentialities. Myrick's law 

 of lost organs. 



Degeneration and extinction of too highly special- 

 ized forms ; Dionaea compared with Drosera. 



When individual self-activity is lowered, and con- 

 ditions of environment are such that destruction does 

 not set in, we have conditions of continuous degenera- 

 tion. Origin of degenerate forms shown by embry- 

 ology. For the individual in its development goes 

 over the whole road, be it upward or downward. 



Amblyopsis, the blind fish, descended from Cholo- 

 gaster, the fish of the Dismal Swamp. Deep sea fishes. 

 Typhlogobius, the blind goby of Point Loma. 



Tunicates, and their fish-like young. 



Sacculina, and its crab-like progeny. Born as a 

 young crab, but, living at the expense of others, loses 

 self-activity, but is not destroyed in competition, 

 and is degraded into a parasitic sac, with no organs 

 except root-processes, ovaries, and brain. Further 

 degradation of male sacculina. 



