-00 CONSERVATIVE ORGANS. [LECT. V. 



plants, consist chiefly of cellular and vascular 

 textures, interspersed with slender bundles of 

 woody fibre. In both the epidermis or exterior 

 covering is the same, and seemingly destitute of 

 vessels : it is present in every stage of the growth 

 of the root from its origin, on the radicle of the 

 embryon, to the tangled rugged arms which rivet 

 down the venerable monarch of the wood, the 

 pride of centuries : it serves the office of a filter, 

 and allows nothing to pass through its pores that 

 cannot enter the minute mouths of the absorbent 

 vessels which open on the surface of the bark 

 beneath it. The epidermis of roots is thus adapted 

 for its situation in the moist soil; but, in other re- 

 spects it does not differ from that which is spread 

 over the stem, branches, leaves, and every other 

 part of the plant, thejibfik, which are attached 

 to all roots, whatever may be their figure, are, as 

 has been already stated, mere bundles of vessels 

 enclosed in a cuticular membrane ; and, as they 

 take up from the earth the food of the plant, they 

 are, in fact, the real roots ; whilst the caudex may 

 be regarded as a magazine, in which the food that 

 has been elaborated into the proper juice is de- 

 posited for the particular uses of the vegetable 

 economy ; and it is this deposition which affords 

 the colour and odour which distinguish different 

 roots. 



With regard to the mode of growth of the 



