266 BIOLOGY. 



tation ; the process of the stalk must consequently be 

 regarded as a vital process of fermentation. 



1408. The process of fermentation is that of putrefac- 

 tion carried on in the air, or the polar process of fermen- 

 tation. Both processes consequently observe a polar re- 

 lation towards each other. 



1409. The sugar-process passess over finally into 

 acidification. 



1410. The Inflammables, as the aetherial oils, balsams, 

 and resins, are formed in the antagonism of the sugar or 

 of the acids. Here also belong most of the peculiar 

 vegetable matters, as the milky saps, colouring matters, 

 medicinally active bodies, poisons, and the alkaloids. 



C. Tracheal-processes. 



a. Leaf-process Inspiration. 



1411. In the foliage the woody rings have issued 

 freely into the air, in order that they may offer their 

 whole surface to its influence, and thus become electrified 

 and oxydized. 



1412. The leaf is the free, external organ of respira- 

 tion to the plant ; it is its lung. Through the leaf the 

 air, and chiefly its oxygen, is transferred into the plant, 

 just as it is through the lungs into the animal. 



1413. The leaves take in oxygen gas; this is their 

 essential function, and not that of exhaling it. 



1414. The leaves only exhale oxygen gas when ex- 

 posed to light. The development of oxygen in the plant 

 is accordingly a light- and not an air -process. In conse- 

 quence of this the leaves give out oxygen gas only during 

 the day, but during the night and even upon gloomy 

 days, where not the light but only the air is active, they 

 take in oxygen and give out carbonic acid. 



1415. The light develops the oxygen gas out of the 

 plant in a perfectly inorganic manner, like as from every 

 water, that can be set in a process of tension. Eurnford 

 has developed by simple glass tubes oxygen gas out of 



