PREFACE xiii 



since been found. This feather is as perfect as are 

 those of the present-day eagle. 



We are informed that mammals have been developed 

 from fish forms. It is pointed out that fishes, birds, and 

 mammals are all built on the same plan, and have all the 

 same skeleton, modified only so far as to be adapted in 

 each case to the requirements of their mode of existence. 

 This is, of course, important and interesting, but in 

 the absence of all other signs it does not help us in 

 our endeavour to ascertain how the evolution from 

 one form to another took place. I do not know that 

 any Darwinian has attempted to explain how the 

 process of evolution towards a mammal structure 

 could have begun in a fish and continued to a 

 consummation. 



It would be interesting from a scientific point of 

 view to peruse an intelligent, even if purely conjec- 

 tural, disquisition as to how much was done under 

 the water and how much was left to be finished on 

 land, and at what point of development and in what 

 manner the organism left the water to begin its life 

 on the land. There is not by any means the same 

 perplexing problem when we seek to account for the 

 transference of mammals from a land existence to a 

 life in the deep sea, such as has happened in the case 

 of whales and porpoises. We have only to assume 

 that certain amphibious mammals were created or 

 evolved whose habitats were by the sea, which 

 gradually became more and more aquatic in then- 

 habits, becoming thereby more adapted to a life in 



