16 ORGANIC EVOLUTION 



Salisbury's Presidential Address to the British 

 Association at its Oxford meeting in 1894. That 

 piece of unprofitable banter may be mercifully for- 

 gotten. Ten years later Lord Salisbury's nephew 

 succeeded to his honour, and readers of Mr. Balfour's 

 Address at Cambridge in 1904 will remember that 

 the nephew took for granted, and assumed as the 

 foundation of his argument, that against which the 

 uncle had inveighed ten years before. 



At the present day the theory of evolution is the 

 guiding principle to and from which all biological 

 studies are directed. It has led directly to the 

 discovery of many facts, and has suggested countless 

 fruitful lines of research. This principle, and this 

 alone, has imparted meaning and intelligibility to 

 thousands — to tens of thousands— of facts in zoology 

 and botany ; and has been the architect of these 

 sciences, taking a collection of unrelated and appa- 

 rently "arbitrary" facts, unworthy of the name of 

 science, and building them into a stately edifice, 

 which stands four-square to all the winds that blow. 

 About the fact of organic evolution no biologist now 

 disputes ; controversy has for many years confined 

 itself to the modes of evolution, and to their relative 

 importance ; one school, known as the Neo-Dar- 

 winians, following Weismann, but not Darwin, in 

 the belief that natural selection alone accounts for 

 all the facts, whilst another, known as the Neo- 

 Lamarckians, follow Spencer in declaring that the 

 inheritance of acquirements plays a part. Recent 

 physical advances — notably the discovery of radium 

 — have removed the discrepancies between the 

 geological time-table and that of the mathematical 



