214 BIOLOGY. 



nor is worthy and susceptible of any philosophical con- 

 struction. 



2. TUBULAR SYSTEM, LIBER. 



1080. As the plant draws in its nourishment from 

 without, so is the main proportion of the sap necessarily 

 present in the periphery of the spiral vessels. The 

 elongated cells in the neighbourhood of the spiral vessels, 

 and which principally contain sap, are called Liber. 



1081. Liber is necessarily present around every packet 

 of spiral vessels, and thus with fasciculi everywhere dis- 

 persed throughout the stem. The liber is only situated 

 beneath the bark, when the number of the spiro-vascular 

 fasciculi is so great, that they form a closed circle in the 

 parenchyma ; it is only beneath the bark, in so far as it 

 accompanies the spiral vessels, but can only surround 

 the latter from without. As it is only the woody plants 

 that have been usually examined, the false idea has thus 

 originated of the liber having, as it were from its very 

 essence, to be beneath the bark. 



1082. In the liber is the main seat of vegetable ac- 

 tivity. Tor it is soft cellular tissue with open intercel- 

 lular passages, wherein the sap can move. 



1083. Now as every fascicle of spiral fibres is sur- 

 rounded by liber, such a fascicle must be regarded as a 

 whole plant. A plant consists accordingly of as many 

 plants, as it has or can have tracheal fasciculi. Every 

 plant is a trunk of infinitely numerous plants ; for every 

 one can contain infinitely numerous tracheal fascicles. One 

 plant is a whole vegetable world. (Ed. 1st, 1810. 

 1065.) 



3. CELLULAR-SYSTEM, BARK. 



1084. No spiral vessels lie upon the surface of the 

 plant, for where they originate, there the liber forms 

 around them, and this is consequently the External. The 

 surface of plants is therefore necessarily environed by 

 liber, notwithstanding the greater influence of the light. 

 The cellular tissue upon the surface of plants is, however, 



