THE PRESIDENTIAL ADDRESS S 



shall be ready with acknowledgment to retract my opinion, which 

 I am not so in love with, but for the sake of Truth I can chearfully 

 cast off without the least reluctancy.' 



One chief object which, as I believe, Huxley had before him was to 

 bring forward a calm, clear statement of the evidence on which 

 alone it was possible to achieve that ' reconstruction of an extinct 

 animal from a tooth or bone,' which had made so deep an impression 

 on the imagination. The reconstruction was in fact a simple 

 inference based on anatomical experience such as that gained by 

 Steno when he dissected the shark and concluded that the ' glosso- 

 petrae ' were the teeth of shark-like fishes. But this reasoning — 

 that a fossil tooth or bone on the surface of a rock, cannot by itself 

 enable the geologist to predict that a skeleton of a certain type lies 

 hidden beneath — seeming to diminish the glory of Cuvier's splendid 

 work, was resented by Owen who had replied with the bitter taunt 

 that a tooth can tell us a great deal — a donkey can kick his master 

 but he cannot eat him. This may have been the encounter referred 

 to by Huxley when he wrote of a friendly meeting with Owen at the 

 Zoological Section of the Association in Leeds (1858) : ' so that 

 the people who had come in hopes of a row were (as I intended they 

 should be) disappointed.' ^ In the same spirit, I think, Huxley 

 was glad to speak of the ' glossopetras ' at the Jubilee meeting, where 

 Owen was President of a Section, and calmly and simply, to reaffirm 

 conclusions which are unassailable. 



Huxley then passed on to Steno 's further study of fossils and his 

 proof of their relationship to terrestrial freshwater and marine 

 organisms, and to his application of this evidence to the past condi- 

 tion of Tuscany — all discussed ' in a manner worthy of a modern 

 geologist ' and later extended by Buffon to all parts of the world 

 then known to be fossiliferous. These conclusions, ' which almost 

 constitute the framework of palaeontology,' only required one 

 addition, made towards the end of the eighteenth century by William 

 Smith, who showed that geological strata contained characteristic 

 fossils so that rocks of the same age could be identified in all parts of 

 the world, while the biologist could follow the changes in the living 

 population of the globe — a record of constant extinction and con- 

 tinual generation of new species. We were then led to three general 

 conclusions : (i) the vast length of time during which life has 

 existed on the earth — ' certainly for millions of years ' ; (2) the 

 continual changes which living forms have undergone during this 

 period ; (3) the successive changes in the best-known fossil groups 

 are such as we should expect if each series ' had been produced by 

 the gradual modification of the earliest form. . . .' This last 

 conclusion meant evolution which so completely accorded with 



^ Life and Letters, vol. i, p. 157. 



