CH. XLI. BIOLOGY. 457 



CHAPTER XLI. 



SCIENCE OF THE NINETEENTH CENTURY (CONTINUED) 



Facts which led Naturalists to believe that the Different Kinds of 

 Animals are descended from Common Ancestors Darwin Wallace 

 Theory of Natural Selection Selection of Animals by Men 

 Selection by Natural Causes Difficulties in Natural History which 

 are explained by this Theory Foolish Prejudices against it Present 

 state of Biological Science Carnivorous Plants Fertilisation of 

 Plants Weissman on Germ-plasma New Zoological Classifica- 

 tions Discoveries of Fossil Animals Links in the Animal Series 

 Concluding Remarks. 



Pacts which have led Naturalists to believe that 

 the different kinds of Animals are descended from 

 common Ancestors. We now come to the first attempt 

 of any value which has ever been made, to explain how the 

 different kinds of animals and plants have been produced. 

 This question is so very difficult, and seems so much 

 beyond our grasp, that we find very few people throughout 

 the history of science who even tried to answer it. Aris- 

 totle, it is true, remarked that we can trace such a close 

 resemblance between the different species, from the lowest 

 plant up to the highest animal, as would seem to show they 

 are related to each other (p. 16). Bonnet, too, thought 

 that animals were developed from lower into higher forms 

 /p. 202); and Lamarck, as we have seen, boldly suggested 

 the same explanation (p. 429). 



But people in general treated these as mere wild specu- 

 lations, and were content to say that God had created 

 animals just in the same way as they said that the stars 



