162 DETAILED SYNTHESIS. 



will be able to exhibit heat in addition to other power. 

 It therefore may be expected, as is the fact, that when 

 the nutritive Principles are decomposed in the animal, 

 they will, in addition to the peculiar power they exert, 

 either produce heat or supply a compound that can by 

 further decomposition exhibit heat. 



Remark. THE NUTRITIVE PRINCIPLES MUST EXIST in other parts be- 

 sides the seeds, since graminivorous animals, eating only the herbage, 

 supply all their tissues with nutriment ; but they eat a very large quan- 

 tity of food. Granivorous animals eat less to gain the same nutriment, 

 carnivorous still less. 



75. UNFORTUNATELY WE DO NOT UNDERSTAND the 

 precise nature of the sun's influence upon vegetable con- 

 struction ; therefore it cannot be spoken of very definite- 

 ly, and only a brief and unsatisfactory statement of 

 leading facts can be given. 



76. THE NUTRITIVE ELEMENTS MUST BE COMBINEP 

 under the influence of the sun's rays, since the plant 

 cannot alone do the work ; nor can it, even if assisted by 

 chemical influences, combine the Elements into Organic 

 Principles without the sun's aid : therefore the power of 

 the sun may be said to be represented in the Principles 

 that are indeed compounds of Chemical Elements and 

 chemical, solar, vegetable, and sometimes animal, influ- 

 ences. 



77. THE VITAL INFLUENCES OF A PLANT ARE always 

 constructive, growing, or productive of growth, while 

 chemical influences are either constructive or destruc- 

 tive, according to circumstances ; and, on the other hand, 

 strictly speaking, all animal processes are destructive. 

 Secretion is truly vegetable in its character, though in 

 the animal modified by nervous influences in some cases. 

 Thus, as chemical influences reach up and coact in the 

 plant, so do chemical and vegetable reach up and coact 

 in the animal. 



Remark. Where -? 75. What -? 76. How -? 77. How -? What is 

 gecretion ? 



