THE naturalist's OCCUPATION. 3 1 



phological and physiological sciences, shows how far the 

 reconstruction of the tree of life has been carried, and 

 thus furnishes a chart which is invaluable as a guide in 

 the selection of subjects for investigation. 



When the classifier, or taxonomist as he is sometimes 

 called, has taken account of morphological features, 

 modes of reproduction, habits, instincts, and distribu- 

 tion, he has exhausted the resources of his special 

 province. The conclusions reached and the questions 

 raised are then to be submitted to other departments 

 for revision and further investigation. 



Let us suppose that the preliminary work of naming 

 and describing has been completed, and that the taxono- 

 mist undertakes with purely descriptive data to map out 

 the genealogical tree. With superficial characters alone, 

 it is evident that he could not advance very far, although, 

 according to the supposition, he would have the immense 

 advantage of knowing precisely what the task is. What 

 such an advantage means, becomes clear when we re- 

 member that, with all the light of all the sciences, we 

 waited until the last half of the nineteenth century for 

 the formulation of the problem. With this key to the 

 situation, a quarter of a century has outdone the blind 

 plodding of all previous centuries, and the old landmarks 

 have been left with a speed that threatens to make Rip 

 Van Winkles of us all. Armed with such an advan- 

 tage, the investigator would certainly be able to find in 

 external characters important clews to genetic relation- 

 ships. But if limited to those methods and means which 

 naturally belong to surface observation, he would remain 

 in absolute ignorance of a great part of the animate 

 world, and would be utterly powerless to discover in 



