98 LIFE IN THE SEA [OH. 



The proximate food-stuffs are : 



/Proteid, splitting to form ammo-acids say, 



leucine, amino-iso-butyl-acetic acid, 

 In the j CH 3 \ PH PH prr/ NH 2 



animal GH */ \COOH 



Fat, say olein . . . C 3 H 5 (OC 17 H 33 CO) 3 



\Cane sugar ......... C^H^On 



[Nitrate, say sodium nitrate ... NaNO 3 

 ln . the J Carbon dioxide ... CO 2 



P lant (Water ...... OH 2 



The proximate food-stuffs, the amino-acids, the 

 fats, and carbohydrates are the same in each case. 

 The foods are also the same, that is they are proteids, 

 fats, and soluble carbohydrates. The process of 

 assimilation, that is the incorporation of these foods 

 by the bioplasm of the cells is also the same. The 

 difference is in the preparation of the proximate food- 

 stuffs, for in order to obtain these the animal must 

 break down material which it can only obtain from 

 the tissues of other animals or plants materials 

 which are highly complex in structure, and it must 

 then synthesise these to form its food-stuffs. The 

 plant builds up its food-stuffs from inorganic material 

 possessing almost the simplest chemical structure 

 known to us. The difference is expressed by saying 

 that the functions of the plant organism are in the 

 main synthetic, or constructive ones, while those of 

 the animal are, in the main, analytic, or destructive 



