18 BIOLOGICAL SOCIETY OF WASHINGTON. . 



« 



produced by them, provided the changes acquired are common 

 to the two sexes, or to those that have produced these new 

 individuals." * 



These laws are enforced bj' considerable iteration and all the 

 facts and illustrations that he could command. He condenses 

 his first law into the following form : 



"The frequent exercise of an organ which through habit 

 has become permanent increases the capacity of such organ, 

 develops it, and causes it to acquire dimensions and power of 

 action which it does not possess in animals that exercise it 

 less."t 



The second law is re-stated in the following language : 



" Every change acquired in an organ by an habitual exercise 

 sufficient to have brought it about, is preserved thereafter 

 through heredity {generatioii) if it is common to the indi- 

 viduals which, in fecundation, unite in the reproduction of 

 their species." % 



Such is Lamarckism pure and simple, which it seems neces- 

 sary to set forth at first hand before approaching those modern 

 phases of the problem which have grown out of it. It is obvi- 

 ous that it deals onh^ with the first of the two agencies in bio- 

 logic progress mentioned at the outset, namely the functional ; 

 and Lamarck, although he clearly grasped the law of compe- 

 tition, or the struggle for existence, the law of adaptation, or 

 the correspondence of the organism to the changing environ- 

 ment, the transmutation of species, and the genealogical de- 

 scent of all organic beings, the more complex from the more 

 simple ; he nevertheless failed to conceive the selective princi- 

 ple as formulated by Darwin and Wallace, which so admirably 

 complemented these great laws. 



*Op. cit., Vol. I, pp. 235-236. top. cit.. Vol. I, p. 247. 



J Op. cit., Vol. I, i)i>. 2.SS-259. 



