THE ADVANCE OF SCIENCE 125 



species by the survival of selected races in the struggle 

 for existence are more firmly established than ever. 

 And this because there have been many attempts to 

 gravely tamper with essential parts of the fabric 

 as he left it, and even to substitute conceptions for 

 those which he endeavoured to establish, at variance 

 with his conclusions. These attempts must, I think, 

 be considered as having failed. A great deal of valuable 

 work has been done in consequence; for honest criti- 

 cism, based on observation and experiment, leads to 

 further investigation, and is the legitimate and natural 

 mode of increase of scientific knowledge. Amongst the 

 attempts to seriously modify Darwin's doctrine may be 

 cited that to assign a great and leading importance to 

 Lamarck's theory as to the transmission by inheritance 

 of newly ' acquired ' characters, due chiefly to American 

 palaeontologists and to the venerated defender of such 

 views, who has now closed his long life of great work, 

 Mr. Herbert Spencer ; that to attribute leading import- 

 ance to the action of physiological congruity and incon- 

 gruity in selective breeding, which was put forward by 

 another able writer and naturalist who has now passed 

 from among us, Dr. George Romanes ; further, the views of 

 de Vries as to the discontinuity in the origin of new 

 species, supported by the valuable work of Mr. Bateson 

 on discontinuous variation ; and lastly, the attempt to 

 assign a great and general importance to the facts as- 

 certained many years ago by the Abbe Mendel as to 

 the cross-breeding of varieties and the frequent produc- 

 tion (in regard to certain characters in certain cases) 

 of pure strains rather than of breeds combining the 

 characters of both parents. On the other hand we 

 have the splendid series of observations and writings 

 of August Weismann, who has, in the opinion of the 



