yS Elliot, Inheritance of Acquired Characters. [Junuary 



ascertain what is meant by the expression "acquired characters." 

 Weisinann* defines these, as "no more than local or sometimes 

 general variations which arise under the stimulus provided by 

 certain external influences." Prof. Ray Lankester,! one of the 

 most ardent as well as aggressive of Weismann's followers, ex- 

 plains the term as "new characters acquired by the parent as the 

 direct consequence of the action of the environment upon the 

 parental structure, and exhibited by that pai'ent as definite meas- 

 urable features." 



Mr. DyerJ gives his view of this expression, in perhaps not 

 quite so lucid a manner, as follows: "Acquired characters are 

 those changes of hypei"trophy, extension, thickening, and the 

 like, which are obviously due to the direct physical action of the 

 environment on the body of the individual organism." 1 would 

 define this term, as seems most reasonable to me. as follows : 

 Acquired characters are diftbientiations due to any cause, known 

 or unknown, assumed by an individual or individuals during 

 life, which render it or them recognizable as varying from the 

 ancestral form. I do not profess to be able to produce proofs 

 that are absolute, and show causes for these variations which may 

 not be explained away by some unexplainable theory, any more 

 than have VVeismann and his followers been able to bring for- 

 ward any that absolutely prove the position they have assumed to 

 be correct, but I think evidence can be given, that may be called 

 strongly circumstantial, if not direct, to show that characters have 

 been acquired and then transmitted by a parent to its oft'spring. 

 We will first consider the causes that, as has been asserted, pro- 

 duce these variations, and then cite some of the cases that would 

 seem to show direct evidence of the power some of these causes, 

 at least, have exerted in influencing these variations, and of flieir 

 transmission from the parent to the oflspring. 



Weismann and his followers, as lias been stated, assert that 

 natural selection is all-sufficient to explain these phenomena. 

 What is natural selection? For a reply I turn to Darwin, the 

 originator of this theory, and read as follows: "The preserva- 

 tion of favorable variations, and the rejection of injurious varia- 



* Essays, p. 171. 



\ Nature, 1890, p. 315. 



J Ibid. 1889, p. 128. 



