THE METHOD 103 



of variations, and therefore a general law, reaching 

 every form of organic life. This is rendered more 

 probable by the discovery by De Vries that variations 

 appear periodically, and are then quite distinct. 



DARWIN'S SAGACITY. Scientists are now very much 

 more amply equipped for the solution of the problems 

 of evolution than Darwin was, but it is wonderful how 

 his interpretation of his wealth of facts has stood the 

 test for more than a half century of critical investiga- 

 tion by the ablest men of genius. The wealth of material 

 now is incomparably greater than in his time. It is 

 found that the principle of evolution becomes more firmly 

 established, and that only here and there is his method, 

 and an occasional inference therefrom, challenged. 



Selenka's investigations of embryos, of different 

 groups of monkeys, have filled up the blank in Dar- 

 win's proofs of the near kin of man, and anthropoid 

 apes. Since Darwin, the Pithecanthropus has been 

 found in the tertiary deposits of Java, which is prob- 

 ably a missing link. Other fossil forms found in other 

 places, are thought by those most qualified to testify, 

 to be additional proofs in paleontology, of the evolu- 

 tion of man from a lower order. 



Experiments have been made in the mixing of the 

 blood of man with mammals of different groups. The 

 reactions, it is claimed, show that the anthropoid ape is 

 nearer akin to man than any other animal. 



THE UTILITY OF INVESTIGATION. It might be asked 

 by the reader who has not made a study of biology and 

 physics, "Why is it desirable to have a great variety of 

 species in the organic kingdom?" and "what difference 

 to the human being is it, how the species arise ? ' ' 



A sufficient answer to the first question is, that if 

 all animals were of one species they would devour one 

 kind of food only, and that food would soon become 



