26 UNIVERSALITY OF DEGENERATIVE EVOLUTION 



Acraspedotc, on the outside of the umbrella being 

 separated from the central part, the two separate 

 parts continue to lash the water, the outer part 

 with even strokes, the central mass more slowly 

 and feebly. With the Craspedote, on the other 

 hand, the central part, under the same conditions 

 seems quite paralyzed and immovable, while the 

 outer part continues to move in a perfectly normal 

 manner. The causative function of the movement, 

 the spontaneity of the movement as it was formerly 

 called in physiology, is incompletely specialized in 

 the Acraspedote, whereas in the Craspedote it is 

 entirely localized. 



Individual adaptation. The individual is by 

 no means a slave to heredity. It is capable of 

 certain modifications under the influence of certain 

 external conditions. These phenomena of individual 

 adaptation may be arranged in three groups. 



(a) When an organism, either animal or vegetable, 

 is placed under new conditions of existence, when 

 for instance, it relinquishes a terrestrial for an 

 aquatic life, light for darkness, or fresh water for 

 salt or esturine water, its external aspect, and in- 

 ternal structure, undergo variations of considerable 

 importance if it succeeds in adapting itself to the 

 new conditions. 1 



1 EXAMPLES : () The leaves of the water Ranunculus with 

 lacinated leaves (Ranunculus aquatilis fluitans, etc. ), are of normal 

 structure when cultivated on diy land. The epidermis is furnished 

 with stoinata and the constituent cells contain no chlorophyll. 



