ADAPTATION 207 



direct action of the external conditions of life, 

 and from use and disuse; a rate of increase so 

 high as to lead to a struggle for life, and as a 

 consequence Natural Selection entailing diver- 

 gence of characters and the extinction of less 

 improved forms." 



I. A Plea foe the Naturalist. I can not 

 close this paper without a plea for the naturalist 

 and systematic zoologist. " Analysis," says Rus- 

 kin, "is an abominable business. I am quite 

 sure that people who work out subjects thor- 

 oughly are disagreeable wretches. One only feels 

 as one should when one doesn't know much about 

 the matter." 



The systematic zoologist is Hable to lose sight 

 of the woods on account of the trees, and follow 

 the example of Jean Paul Richter's Quintus 

 Fixlein, who collected a vast number of typo- 

 graphical errors, assured the public that valuable 

 conclusions could be drawn from them, and left 

 it to some one to draw them. 



The imagination is in Biology as elsewhere the 

 guiding spirit. The trouble is our imaginations 

 are sometimes too heavily loaded with statistics 

 and at other times they fly without the balancing 

 kite's tail of facts. The Paleontologists have 

 contributed so much to speculative zoology be- 

 cause their imaginations have been kept alive by 

 bridging their numerous gaps and because they 

 have not been hampered by too great a wealth 

 of material. 



