26 SCIENCE FROM AN EASY CHAIR 



rocks, and in fitting the ground for the growth of plants, 

 but recorded some discoveries as to the senses of worms 

 and as to their treatment of leaves by a digestive fluid 

 exuded from the mouth so as to soften a leaf before 

 swallowing it. 



Every one of Darwin's books abounds with new facts 

 and new points of view disclosed by the application to 

 first one thing and then another of his vivifying discovery- 

 causing theory of natural selection. The subsidiary theory 

 of the selection of brilliantly coloured males by females 

 in pairing, as a cause of the brilliant colours and patterns 

 of many birds and insects, is developed in his Descent of 

 Man. It led him to many important discoveries and 

 observations as to the colouring and ornamentation of 

 animals, and when considered, together with Wallace's 

 and Bates's theory of mimicry and of the warning and 

 protective colourings of insects, goes far to explain all 

 the specific colouring of animals and plants as due to 

 natural selection and survival. A theory which has pro- 

 duced such prodigious results in the way of "explaining" 

 all forms, colours, habits, and occurrences of living things 

 as has that of Charles Darwin simply holds the field 

 against all comers. When Lamarck's theory has been 

 shown to be consistent with the most elementary facts 

 as to heredity, and further to afford a rational explana- 

 tion of any group of biological facts, it will be time to 

 consider how far it may be entertained in conjunction 

 with Darwin's theory but not until then. 



