ENQUIRY INTO PLANTS, I. ii. 3-5 



the case of some plants give it no special name, while 

 in some they call it 'juice,' and in others "^gum.' 

 Fibre and ' veins ' ^ have no special names in relation 

 to plants, but, because of the resemblance, borrow 

 the names of the corresponding })arts of animals. - It 

 may be however that, not only these things, but the 

 world of plants generally, exhibits also other differ- 

 ences as compared with animals : for, as we have 

 said,2 the world of plants is manifold. However, 

 since it is by the help of the better known that we 

 must pursue the unknown, and better known are the 

 things which are larger and plainer to our senses, 

 it is clear that it is right to speak of these things in 

 the way indicated : for then in dealing with the 

 less known things we shall be making these better 

 known things our standard, and shall ask how far and 

 in what manner comparison is possible in each case. 

 And when we have taken the parts,* we must next 

 take the differences which they exhibit,^ for thus 

 will their essential nature become plain, and at the 

 same time the general differences between one kind 

 of plant and another. 



Now the nature of the most important parts has 

 been indicated already, that is, such parts as the 

 root, the stem, and the rest : their functions and the 

 reasons for which each of them exists will be set forth 

 presently. For we must endeavour to state of what 

 these, as well as the rest, are composed, starting from 

 their elementary constituents. 



First come moisture and warmth : for everj- plant, 

 like every animal, has a certain amount of moisture 

 and warmth which essentially belong to it ; and, if 

 these fall short, age and decay, while, if they fail 

 altogether, death and withering ensue. Now in 



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