THE LIMBS OF LIZARDS 131 



or otherwise to the organism. If advantageous, then 

 they confer a benefit and advantage upon the organism 

 possessing them, which the others do not possess ; and 

 that therefore in the struggle for existence, the former 

 will survive and procreate their species, and the latter 

 will become exterminated. Thus Nature selects the 

 fittest to survive, and rejects the unfit, and hence to 

 the Darwinian theory has been given the name of 

 Natural Selection. Thus may be explained why 

 organisms are adapted to their environment ; not 

 because, as the Lamarckians assert, Nature has in- 

 discriminately moulded them to it, but because those 

 not so adapted have become exterminated." 



It is no part of our purpose to even mention the 

 various arguments for and against these opposing 

 views, every field naturalist can and should become 

 acquainted with them from zoological text - books. 

 What we wish to do is simply to take the case of 

 the slow-worm as an example of a species which has 

 arisen as the result of variation, and apply the two 

 views to it. 



We may suppose that the ancient four-limbed 

 lizard, according to the first of the views enunciated, 

 found itself in the course of time, and in some cir- 

 cumstances of its distribution, under the necessity of 

 taking to a burrowing life or living in loose sand, or 

 in some other condition in which the limbs were not 

 well adapted for locomotion. What the precise nature 

 of the environment was does not matter. Whatever 



