264 Philosophy of Botany. 



four, but generally five, elements — earbon. hydrogen, nitrogen. 

 oxygen, and sulphur — forming the albuminoids, the most com- 

 plex, variable, and vmstable chemical compounds. Here we 

 see how. within the cell, from the circulating nutritive fluid the 

 plastic mass, protoplasm, gradually develops. 



The progress of growth proceeds in animals nearly uni- 

 formly, in plants from the terminal vegetative points — buds — 

 and in the cambium or periph.eral region (green bark). Thence 

 begins the differentiation of tissues, and of the whole series of 

 vegetable and animal bodies, and that mutual interaction by 

 which from the root or stomach nutritive elements are con- 

 veyed and elaborated. The production of protoplasm termi- 

 nates in the maturing and storage of such albuminoids as 

 make up the body of seeds, and fill the cells of tubers, bulbs, 

 roots, and cambium, and provide for the renewal of individual 

 life and nutrition in its infant state. None of the secondary 

 elements or products possess an inherent vitality. The pro- 

 teins, which are the most complex in composition, are exceed- 

 ingly prone to decomposition. The simpler hydrocarbons, like 

 lignin. cellulose, starcli. the resins, only, are enduring. The 

 most obvious of the protoplasmic forms is the chlorophyll, 

 whose principal function is the separation of the carbon in the 

 process of plant respiration. 



Respecting the comparative quantities in the composition of 

 the individual b(Ddies — of proteinic, nitrogenated constitu- 

 ents, and the nonnitrogenated simpler ones — we observe re- 

 verse relation. While in plants the amount of albuminoids is 

 comparatively insignificant, we find the bodies of animals 

 nearly exclusively proteinic. Plants Increase constantly, dur- 

 ing the vegetative period, their supply in albumen, until they 

 enter the resting period. Animals hare, without interruption, 

 to renew it. lest they perish. 



It is meet to remember that all protoplasmic bodies are sub- 

 ject to a constant process of elimination and renewal, and that 

 the suspension of either effects their immediate death, which 

 under all circumstances is their ultimate fate. 



Very different is the problem of the origin of the primitive 

 protoplasm when it takes its rise without the medium of pre- 

 existing protoplasmic bodies. This process is called the " gen- 



