LAMARCK'S THEORY OF DESCENT 



355 



Lamarck [referring to new wants, see p. 346] as com- 

 pared with more modern and now widely received 

 theories, it must be observed that it is only an ex- 

 tension of his third law; and that third law is a fact. 

 The strengthening of the blacksmith's arm by use is 

 proverbially notorious. It is, therefore, only the sufifi- 

 ciency of the Lamarckian hypothesis to explain the 

 first commencement of new organs which is in ques- 

 tion, if evolution by the mere operation of forces 

 acting in the organic world be granted; and surely 

 the Darwinian theory is equally helpless to account 

 for the beginning of a new organ, while it demands 

 as imperatively that every stage in the assumed 

 hereditary development of an organ must have been 

 useful. . . . Lamarck gave great importance to 

 the influence of new wants acting indirectly by stim- 

 ulating growth and use. Darwin has given like im- 

 portance to the effects of accidental variations acting 

 indirectly by giving advantage in the struggle for ex- 

 istence. The speculative writings of Darwin have, 

 however, been interwoven with a vast number of 

 beautiful experiments and observations bearing on 

 his speculations, though by no means proving his 

 theory of evolution; while the speculations of La- 

 marck lie apart from his wonderful descriptive 

 labors, unrelieved by intermixture with other mat- 

 ters capable of attracting the numerous class who, 

 provided they have new facts set before them, are 

 not careful to limit themselves to the conclusions 

 strictly deducible therefrom. But those who read 

 the Philosophie Zoologique will find how many truths 

 often supposed to be far more modern are stated 

 with abundant clearness in its pages." (Encyc. Brit., 

 art. " Lamarck.") 



