212 UNIVERSITY OF MISSOURI BULLETIN 



separate its toes when they strike the water. The skin unit- 

 ing the base of the toes will be stretched in consequence, 

 and in this way the broad membrane between the toes of ducks 

 and geese has been acquired." Again, blind fishes living in 

 dark caves have lost their eyesight through disuse of their 

 organs of vision, and each degenerative change thereby pro- 

 duced is passed on to the next generation. Even granting that 

 such profound modifications of the individual organism are 

 possible as the result of use and disuse, the weakness of 

 Lamarck's argument lay in the fact that he assumed without 

 evidence that these acquired changes were transmitted to the 

 offspring, a conclusion which could only be proved by actual 

 observation and experiment; and of course it is manifest that 

 the whole significance of the change as a cause of evolution 

 rests upon the truth of the assumption that individual modifi- 

 cations are transmissible. 



In maintaining a continuity in the development of organic 

 forms, Lamarck rejected Cuvier's theory of "catastrophism" 

 by which the latter attempted to account for the successive 

 series of animals and plants found in the fossiliferous rocks 

 of each geological period. According to this hypothesis a 

 great cataclysm or convulsion of nature has brought to an 

 end each period of the earth's history, with the destruction of 

 all life, and upon the newly prepared earth a fresh and newly 

 created world of species has been placed by the Creator, — 

 only to be wiped out of existence in its turn by the next cata- 

 clysm. 



Lamarck's spirited writings received but scant attention 

 at the hands of his immediate contemporaries, and met with 

 only contempt from Cuvier, the great zoological authority of 

 France at the time, who spoke of each edition of his works 

 as a nouvelle folic. We see here one of the many instances, 

 in which the history of science abounds, of accepting as final 

 the premature condemnation of a new hypothesis. 



