VI ANIMALS AND PLANTS 163 



divided from the earliest times into animated 

 beings, which possess sense and motion, and inani- 

 mated leings, which are devoid of these functions 

 and simply vegetate. 



Although the roots of plants direct themselves 

 towards moisture, and their leaves towards air and 

 light, although the parts of some plants exhibit 

 oscillating movements without any perceptible 

 cause, and the leaves of others retract when 

 touched, yet none of these movements justify the 

 ascription to plants of perception or of will. From 

 the mobility of animals, Cuvier, with his charac- 

 teristic partiality for teleological reasoning, de- 

 duces the necessity of the existence in them of an 

 alimentary cavity, or reservoir of food, whence 

 their nutrition may be drawn by the vessels, which 

 are a sort of internal roots ; and, in the presence 

 of this alimentary cavity, he naturally sees the 

 primary and the most important distinction be- 

 tween animals and plants. 



Following out his teleological argument, Cuvier 

 remarks that the organisation of this cavity and 

 its appurtenances must needs vary according to 

 the nature of the aliment, and the operations 

 which it has to undergo, before it can be converted 

 into substances fitted for absorption ; while the 

 atmosphere and the earth supply plants with 

 juices ready prepared, and which can be absorbed 

 immediately. As the animal body required to be 

 independent of heat and of the atmosphere, there 



M 2 



