ACQUIRED CHARACTERS xxxix 



organic evolution ; he expressly excludes direct action as 

 an operative cause. But before dealing with Lamarck's 

 general views on this subject, I propose to cite a number of 

 the facts upon which he relied for the proof of his theory. 



Domestic races, both of animals and plants, are very 

 different from the ancestral wild races from which they spring. 

 When the environment is greatly altered, the structure of 

 the organism undergoes a corresponding alteration. Take, 

 for instance, the various races of dogs. They are, according 

 to Lamarck, all descended from an animal something like a 

 wolf. They became domesticated by man, and were trans- 

 ported by him to different parts of the earth, where the 

 environment was very different from their natural home. 

 Accordingly, they underwent modifications in each locality, 

 which brought them into harmony with the conditions pre- 

 vailing in that locality. These modifications, being inherited 

 through many generations, acquired comparative stability ; 

 and the new varieties, when imported into a new country 

 or great city, would for a long period retain their general 

 characteristics. These would be further complicated by 

 inter-breeding, and thus give rise to the many different 

 varieties with which we are acquainted. So argued Lamarck. 



Where an animal does not use its teeth, these dwindle 

 and disappear. Such, for instance, is the case with right- 

 whales and ant-eaters, although Geoffrey Saint-Hilaire dis- 

 covered rudimentary teeth in the foetus of right-whales. 

 The same applies to birds, where teeth have become still 

 more completely extinct. 



Animals which do not use their eyes, such as moles, after 

 a time lose the use of that organ either completely or 

 partially. 



Snakes would be impeded by legs, and have consequently 

 lost them. Their mode of life requires them to hide in 

 grass, and to pass through narrow crevices. Hence, urges 

 Lamarck, their bodies become narrow and long. Long legs 

 would greatly interfere with their mode of life : short legs 

 would be incapable of supporting them, since (being reptiles) 



