CLASSIFICATION Ixiii 



due to inheritance of acquired characters. Lamarck supposes 

 that some race of apes conceived a desire to obtain distant 

 views over the country, and for that reason contracted the 

 habit of standing up on their hind legs, to get a better view. 

 The constant assumption of this posture would, according 

 to Lamarck, produce suitable modifications of structure, 

 which would be inherited : in course of many generations, 

 the erect position would become the normal one. The modi- 

 fications of feet and jaws are accounted for on similar lines. 

 Lamarck assumes that as the human race became dominant, 

 it would everywhere be brought in contact with a new 

 environment, develop new wants, and make efforts for the 

 satisfaction of these wants. These efforts would result in 

 corresponding structural alterations, which would be inherited. 

 Thus, he regards the origin of language as due to the constant 

 efforts to impart ideas. These efforts, by use-inheritance, 

 would cause the necessary development of the throat, mouth 

 and lips. When once language had been acquired, and 

 conventional signs agreed upon, man had scattered over the 

 earth, varieties of the original language had arisen, until 

 ultimately the existing diversity of languages was attained. 

 Meanwhile the development of other races of apes would be 

 hindered by that of man, for man would persecute them and 

 drive them from the hospitable regions of the earth. But 

 all this is merely put forward as an hypothesis, to explain 

 how the structure of man might have been derived from 

 simian ancestry by ordinary biological laws : but Lamarck 

 cautiously repudiates at the end any suggestion that he did 

 arise from simian ancestry. 



In his later classification, printed in the " Additions " to 

 Part I., Lamarck made certain improvements in his classifica- 

 tion, in the direction of abandoning the linear series. He 

 held that the animal kingdom originated by spontaneous 

 generation in two independent roots, the infusorians and 

 the worms. From the former were derived the polyps and 

 radiarians alone. The worms, on the other hand, or at 



