^^^^ ZOOGENESIS ®il 



reptiles, there are many well marked, obvious, and 

 undeniable evolutionary lines v^hich, beginning with 

 a relatively simple form of creature run by easy stages 

 to a specialized and highly complex form. 



In the second place, very few of these evolutionary 

 lines are perfectly continuous . Practically all of them 

 are more or less interrupted by gaps of various widths, 

 and these gaps are often very broad. Especially is it 

 true that these evolutionary lines tend to be separated 

 from each other for their entire course, running paral- 

 lel or more or less convergent right down to their very 

 earliest beginnings, and not uniting in a common type 

 of animal as we would expect. For instance, the 

 whales and the seals are always whales and seals, and 

 show little or no approach to any other type of 

 mammal. Similarly, there are no intermediates be- 

 tween turtles and snakes, or between turtles and 

 lizards, all of which are reptiles, or between squid 

 (fig. 45, p. 97) and oysters, though both types are 

 mollusks. 



In the third place, no animals are known even from 

 the very earliest rocks which cannot be at once as- 

 signed to their proper phylum or major group on the 

 basis of the definition of that group as drawn up from 

 a study of living animals alone. A backboned animal 

 is always unmistakably a backboned animal, a star- 

 fish is always a starfish, and an insect is always an 

 insect no matter whether we find it as a fossil or catch 

 it alive at the present day. There can be only one 

 interpretation of this entire lack of any intermediates 

 between the major groups of animals, as for instance 



