i88o COMING OF AGE OF THE ORIGIN OF SPECIES 13 



So dire a consummation, he declared, must be prevented 

 by unflinching criticism, the essence of the scientific spirit, 

 " for the scientific spirit is of more value than its products, 

 and irrationally held truths may be more harmful than 

 reasoned errors.'' 



What, then, were the facts which justified so great a 

 change as had taken place, which had removed some of the 

 most important qualifications under which he himself had 

 accepted the theory? He proceeded to enumerate the 

 " crushing accumulation of evidence " during this period, 

 which had proved the imperfection of the geological record ; 

 had filled up enormous gaps, such as those between birds 

 and reptiles, vertebrates and invertebrates, flowering and 

 flowerless plants, or the lowest forms of animal and plant 

 life. More : paleontology alone has effected so much — the 

 fact that evolution has taken place is so irresistibly forced 

 upon the mind by the study of the Tertiary mammalia 

 brought to light since 1859, that " if the doctrine of evolu- 

 tion had not existed, paleontologists must have invented it." 

 He further developed the subject by reading before the 

 Zoological Society a paper " On the Application of the Laws 

 of Evolution to the Arrangement of the Vertebrata, and 

 more particularly of the Mammalia "' (Proc. Z. S. 1880, 

 pp. 649-662). In reply to Darwin's letter thanking him 

 for the ." Coming of Age " (Life and Letters, iii. 24), he wrote 

 on May 10: — 



My dear Darwin — You are the cheeriest letter-writer I 

 know, and always help a man to think the best of his doings. 



I hope you do not imagine because I had nothing to say 

 about " Natural Selection," that I am at all weak of faith on 

 that article. On the contrary, I live in hope that as palaeon- 

 tologists work more and more in the manner of that " second 

 Daniel come to judgment," that wise young man M. Filhal, we 

 shall arrive at a crushing accumulation of evidence in that 

 direction also. But the first thing seems to me to be to drive 

 the fact of evolution into people's heads; when that is once 

 safe, the rest will come easy. 



I hear that ce cher X. is yelping about again ; but in spite of 

 your provocative messages (which Rachel retailed with great 

 glee), I am not going to attack him nor anybody else. 



