VII. 



ON THE SUPPOSED BOTANICAL PROOFS 



OF THE 



TRANSMISSION OF ACQUIRED CHARACTERS. 



IN a lecture on heredity, delivered in 1883 VI first brought 

 forward the opinion that acquired characters cannot be transmitted; 

 and I then stated that there are no proofs of such transmission, 

 that its occurrence is theoretically improbable, and that we must 

 attempt to explain the transformatio of species without its aid. 

 Since that time many biologists have expressed their opinions 

 upon the subject, some of them agreeing with me, while others 

 have taken the opposite side. It is unnecessary to allude to those 

 who have attacked my opinions without first understanding the 

 real point in dispute, which turns upon the true meaning of the 

 phrase ' acquired character.' I think it is now generally admitted 

 that a very important problem is involved in this question, the 

 solution of which will contribute in a decisive manner towards 

 the formation of ideas as to the causes which have produced the 

 transformation of species. For if acquired characters cannot be 

 transmitted, the Lamarckian theory completely collapses, and we 

 must entirely abandon the principle by which alone Lamarck 

 sought to explain the transformation of species, a principle of 

 which the application has been greatly restricted by Darwin in 

 the discovery of natural selection, but which was still to a large 

 extent retained by him. Even the apparently powerful factors 

 in transformation the use and disuse of organs, the results of 

 practice or neglect cannot now be regarded as possessing any 

 direct transforming influence upon a species. And the same is 

 true of all the other direct influences, such as nutrition, light, 



1 See the second Essay ' On Heredity.' 

 C C 2 



