324 LAMARCK, HIS LIFE AND WORK 



such habits and those restricted to different habits, 

 then it will be certain that the first conclusion does 

 not conform to the laws of nature, and that, on the 

 contrary, the second is perfectly in accord with them. 



" Everything combines then to prove my asser- 

 tion — namely, that it is not the form, either of the 

 body or of its parts, which gives rise to habits, and 

 to the mode of life among animals ; but that it is on 

 the contrary the habits, the manner of living, and all 

 the other influencing circumstances which have, after 

 a time, constituted the form of the body and of the 

 parts of animals. With the new forms, new faculties 

 have been acquired, and gradually nature has come 

 to form the animals as we actually see them. 



" Can there be in natural history a consideration 

 more important, and to which we should give more 

 attention, than that which I have just stated ? 



" We will end this first part with the principles and 

 the exposition of the natural classification of animals." 



In the fourth chapter of the third part (vol. ii. pp. 

 276-301) Lamarck treats of the internal feelings of 

 certain animals, which provoke wants {besoins). This 

 is the subject which has elicited so much adverse criti- 

 cism and ridicule, and has in many cases led to the 

 wholesale rejection of all of Lamarck's views. It is 

 generally assumed or stated by Lamarck's critics, who 

 evidently did not read his book carefully, that while 

 he claimed that the plants were evolved by the direct 

 action of the physical factors, that in the case of all 

 the animals the process was indirect. But this is not 

 correct. He evidently, as we shall see, places the 

 lowest animals, those without (or what he supposed 

 to be without) a nervous system, in the same category 

 as the plants. He distinctly states at the outset that 



