INTRODUCTION 41 



characteristics of the reptile. Now, we have found two 

 well - preserved skeletons of a reptile - bird of this 

 character. This " archseopteryx " has the distinctive 

 feathers, beak, pelvis, and feet of the bird, and at the 

 same time an articulated lizard-like tail, teeth, and well- 

 formed toes on its fore-feet, which project far out from 

 the wing and are not found in any actual bird, but only 

 in the reptiles. 



A second example : 



Our horse has only one toe, and on this the hoof is 

 placed. The other mammals, even the lower ones, 

 from which it must have evolved, have several toes ; 

 and thus there must have been at a certain stage horses 

 that had at least rudimentary traces of the other toes, 

 besides the developed one. 



As a matter of fact, we have discovered four-toed 

 horses in the geological strata. Indeed, we have 

 brought to light in the successive strata skeletons of 

 horses that illustrate every stage of transition from the 

 ancient four-toed to the modern one-toed horse ; and 

 the nearer the remains approach to our own time, the 

 less trace do we find of the other three toes. 



We could quote a large number of transitional forms 

 from geology, but will be content with these, Let us 

 recall to the reader the way in which we arrived at our 

 theory of evolution. We sought to show that natural 

 selection can transform one species into another, and we 

 found that such a process has been going on uninter- 

 ruptedly in geology. The question arises, therefore : 

 Is it natural selection that thus brought about all these 

 transformations? Is this the artist that has produced 



