72 THE MECHANICAL FUNCTIONS. 



more forcibly will our hearts be impressed with the 

 truth of the divine appeal, that " Even Solomon 



IN ALL HIS GLORY WAS NOT ARRAYED LIKE ONE OF 

 THESE." 



§ 3. Dev elopement of Vegetables. 



Further proofs of design may be collected from an 

 examination into the modes in which these struc- 

 tures, so admirably adapted to their objects, have 

 been gradually formed. Confining our attention 

 to vascular plants, in which the process of deve- 

 lopement has been studied with the greatest atten- 

 tion and success, we find that Nature has pursued 

 two different plans in conducting their growth.* 

 In the greater number, the successive additions to 

 the substance of the stem are made on the exterior 

 side of the parts from which they proceed. This 

 mode is adopted in what are called Exogenous 

 plants. In others, the growth is the result of addi- 

 tions made internally; a plan which is followed in 

 all Endogenous plants. The Oak, the Elm, the 

 Beech, the Pine, and all the trees of these northern 

 regions, belong to the first of these divisions. The 

 Palm tribe, such as the Date, the Cocoa-nut tree, 

 and, indeed, a large proportion of the trees of tro- 

 jiical climates, together with the sugar-cane, the 

 bamboo, and all gramineous and liliaceous plants, 

 belong to the latter. We shall first inquire into 

 the endogenous mode of growth, as being the sim- 

 plest of these two kinds of vegetable developement. 



* The tribe of Filices, or ferns, the structure of which is vascu- 

 lar, constitute an exception to this rule : as they differ in their mode 

 of developement, both from exogenous and endogenous plants. 



