INTRODUCTORY 3 



in Nature. The indefatigable patience, the keen observa- 

 tion, and the sympathetic insight of many of these pre- 

 Darwinian naturalists must remain as models to which in 

 these later days, with improved methods, we try to approxi- 

 mate. Gilbert White's " Selborne," above all, remains 

 evergreen. But the old records are for the most part con- 

 tributions to Natural History rather than to Biology. To 

 most of their authors there was wanting the biological key 

 which Darwin first taught men to use. We mean not merely 

 the idea of organic evolution, that the present is the child 

 of the past, though that is indeed the " Open Sesame " of 

 Nature but other biological conceptions as well of 

 protoplasm and its changes, of the rhythms of life, of effec- 

 tive response to external stimuli, of the correlation of 

 organs and of division of labour, and of the correlation of 

 organisms in the web of life. 



The difference between the old naturalists and the new, 

 which came partly through Darwin's influence and partly 

 because the time was ripe, may be readily perceived if we 

 compare, for instance, the older naturalist-travellers with the 

 new. No one can dispute the virility sometimes rising to 

 greatness of the work done by Thomas Pennant, Peter 

 Pallas, Gesner, Humboldt himself, and the crowd of more 

 specialist -travellers who followed these ; but there is a 

 difference in kind between their results and those embodied 

 in Darwin's Voyage of the Beagle, and in other narratives of 

 naturalists' journeyings by Wallace, Bates, Belt, Moseley, 

 Hickson, Hudson, Rodway, Scott Elliot, Alcock, and some 

 others. Biological ideas have become dominant ; analysis 

 has become more penetrating ; the pictures have a broader 

 perspective and a deeper insight. Through and through we 

 feel that the travellers are dealing, not merely with interest- 

 ing things that they are delighted to describe, but with an 

 evolutionary drama that they are trying to understand. 



