GEOLOGICAL ATTACK 221 



environment. 1 But those who assert that the rate of 

 biological evolution ever differed materially from what 

 it may now be inferred to be, ought surely to bring 

 forward something more than mere assertion in their 

 support. In the meantime, the most philosophical 

 course is undoubtedly followed by those biologists 

 who in this matter rest their belief on their own ex- 

 perience among recent and fossil organisms. 



So cogent do these geological and palaeontological 

 arguments appear, to those at least who have taken 

 the trouble to master them, that they are worthy of 

 being employed, not in defence merely, but in attack. 

 It seems to me that they may be used with effect in 

 assailing the stronghold of speculation and assumption 

 in which our physical friends have ensconced themselves 

 and from which, with their feet, as they believe, 

 planted well within the interior of the globe and their 

 heads in the heart of the sun, they view with complete 

 unconcern the efforts made by those who endeavour 

 to gather the truth from the surface and crust of the 

 earth. That portion of the records of terrestrial his- 

 tory which lies open to our investigation has been 

 diligently studied in all parts of the world. A vast 

 body of facts has been gathered together from this 

 extended and combined research. The chronicle 

 registered in the earth's crust, though not complete, 



a See an interesting and suggestive paper by Professor Le Conte 

 on ' Critical Periods in the History of the Earth,' Bull. Dept. Geology, 

 University of California, vol. i. (1895), p. 313 ; also one by Professor 

 Chamberlin on 'The Ulterior Basis of Time-divisions and the 

 Classification of Geological History,' Journal of Geology, vol. vi. 

 (1898), p. 449. 



