CRITICISM OF LAMARCKS LAWS if i 



first and second laws are QontradLctory the one of the other. In 

 correspondence with the normal conditions of the environment, 

 organisms show " responsive " quantities in their parts ; but. 

 change a young organism to an environment quantitatively 

 different, and it shows new responsive quantities in the parts of 

 its structure concerned, new or acquired characters. 



" So far, so good. What Lamarck next asks us to accept, as 

 his ' second law/ seems not only to lack the support of experi- 

 mental proof, but to be inconsistent with what has just preceded 

 it. The new character, which is ex hypothesi, as was the old 

 character (length, breadth, weight of a part) which it has re- 

 placed a response to environment, a particular moulding or 

 manipulation by incident forces of the potential congenital 

 quality of the race is, according to Lamarck, all of a sudden 

 raised to extraordinary powers." It is declared to be trans- 

 missible, that is, it alters the potential character of the species, 

 so as to persist when other quantitative external conditions are 

 substituted for those which originally determined it. But this 

 has never been experimentally proved, and there is strong 

 reason for holding it to be improbable. 



" Since the old character (length, breadth, weight) had not 

 \become fixed and congenital after many thousands of successive 

 generations of individuals had developed it in response to 

 environment, but gave place to a new character when new 

 conditions operated on an individual (Lamarck's first law), 

 why should we suppose that the new character is likely to 

 become fixed after a much shorter time of responsive existence, 

 or to escape the operation of the first law ? Clearly there is no 

 reason (so far as Lamarck's statement goes) for any such suppo- 

 sition, and the two so-called laws of Lamarck are at variance 

 with one another. 



" In its most condensed form my argument has been stated 

 thus by Prof. Poulton (Nature, vol. li., 1894, p. 127) ; Lamarck's 

 ' first law assumes that a past history of indefinite duration 



