BEFORE DARWIN AND AFTER. 



Life, vegetal and animal, it must be the seat 

 of health and disease. The Cellular Pathol- 

 ogy (1858) of Virchow was in this field epoch- 

 making. But when it began to be conceived 

 that hereditary qualities were transmitted 

 from generation to generation through the 

 cell, biology took a new turn, and entered upon 

 the investigations in which it is at present 

 chiefly engaged. The transmission of physi- 

 cal qualities from ancestors is the theme about 

 which our time is most anxious; the implica- 

 tion is that with physical are transmitted psy- 

 chical qualities. Evolution being granted, we 

 wish to catch it in the very act, to find its 

 secret process. This work has been going on 

 since the Darwinian deed, and it we must 

 scan briefly. 



III. AFTER DARWIN. If we inspect the two 

 terms which compose the title to the Origin 

 of Species, we shall find that origin has a 

 deeper and stronger stress than species. Real- 

 ly Darwin's book is a discussion of organic 

 generation, and turns upon the genesis of the 

 individual organism. This is what is brought 

 decidedly into the foreground in the trend 

 of biology after Darwin. What is the method 

 of the propagation of Life? Such a question 

 goes back in its farthest reach to the funda- 

 mental act of Nature, namely its individu- 

 ation. For Nature does its work through ere- 



