644 '^^E POPULAR SCIENCE MONTHLY. 



ficial pathos ; and the zoological heresies at which the eighteenth cent- 

 ury shrugged its fat shoulders and dimpled the corners of its ample 

 mouth, have grown to be the chief cornerstone of all accepted modern 

 zoological science. 



In the first year of the present century Lamarck followed Erasmus 

 Darwin's lead with an open avowal that in his belief all animals and 

 plants were really descended from one or a few common ancestors. lie 

 held that organisms were just as much the result of law, not of mirac- 

 ulous interposition, as suns and worlds and all the natural phenomena 

 around us generally. He saw that what naturalists call a species differs 

 from what naturalists call a variety merely in the way of being a little 

 more distinctly marked, a little less like its nearest congeners elsewhere. 

 He recognized the perfect gradation of forms by which in many cases 

 one species after another merges into the next on either side of it. He 

 observed the analogy between the modifications induced by man and 

 the modifications induced by Nature. In fact, he was a thorough- 

 going and convinced evolutionist, holding every salient opinion which 

 society still believes to have been due to the works of Charles Darwin. 

 In one point only, a minor point to outsiders, though a point of car- 

 dinal importance to the inner brotherhood of evolutionism, he did not 

 anticipate his more famous successor. He thought organic evolution 

 was wholly due to the direct action of surrounding circumstances, to 

 the intercrossing of existing forms, and above all to the actual efforts 

 of animals themselves. In other words, he had not discovered natural 

 selection, the cardinal idea of Charles Darwin's epoch-making book. 

 For him, the giraffe had acquired its long neck by constant reaching 

 up to the boughs of trees ; the monkey had acquired its opposable 

 thumb by constant grasping at the neighboring branches ; and the 

 serpent had acquired its sinuous shape by constant wriggling through 

 the grass of the meadows. Charles Darwin improved upon all that by 

 his suggestive hint of survival of the fittest, and in so far, but in so 

 far alone, he became the real father of modern biological evolu- 

 tionism. 



From the days of Lamarck to the day when Charles Darwin him- 

 self published his wonderful " Origin of Species," this idea that plants 

 and animals might really have grown, instead of having been made 

 all of a piece, kept brewing everywhere in the minds and brains of 

 scientific thinkers. The notions which to the outside public were 

 startlingly new when Darwin's book took the world by storm, were 

 old indeed to the thinkers and workers who had long been familiar 

 with the principle of descent with modification and the speculations 

 of the Lichfield doctor or the Paris philosoplier. Long before Darwin 

 wrote his great work, Herbert Spencer had put forth in plain language 

 every idea which the drawing-room biologists attributed to Darwin. 

 The supporters of the development hypothesis, he said seven years 

 earlier — yes, he called it the " development hypothesis " in so many 



