XI PALEONTOLOGY AND EVOLUTION 343 



ledge and reflection, and an extreme desire to get 

 at the truth, may afford me. 



1. With respect to the first proposition, I may 

 remark that whatever may be the case among the 

 physical geologists, catastrophic palaeontologists 

 are practically extinct. It is now no part of 

 recognised geological doctrine that the species of 

 one formation all died out and were replaced by a 

 brand-new set in the next formation. On the 

 contrary, it is generally, if not universally, agreed 

 that the succession of life has been the result of a 

 slow and gradual replacement of species by species ; 

 and that all appearances of abruptness of change 

 are due to breaks in the series of deposits, or other 

 changes in physical conditions. The continuity of 

 living forms has been unbroken from the earliest 

 times to the present day. 



2, 3. The use of the word " homotaxis " instead 

 of" synchronism" has not, so far as I know, found 

 much favour in the eyes of geologists. I hope, 

 therefore, that it is a love for scientific caution, 

 and not mere personal affection for a bantling of 

 my own, which leads me still to think that the 

 change of phrase is of importance, and that 

 the sooner it is made, the sooner shall we get rid 

 of a number of pitfalls which beset the reasoner 

 upon the facts and theories of geology. 



One of the latest pieces of foreign intelligence 

 which has reached us is the information that the 

 Austrian geologists have, at last, succumbed to 



