

352- Of Vegetation. 



expofed to a free drying air, they perfpirc 

 plentifully, and thereby drawing the fan to 

 the top, they advance much in height : But 

 vice verfa, if when fuch a Grove of tall 

 trees is cut down, there be left here and 

 there a fingle tree, that tree will then fhoot 

 out lateral branches ; the leaves of which 

 branches now perfpiring freely, will at- 

 tract plenty of fap, on which account 

 the top being deprived of its nourifhment, 

 it ufually dies. 



And as trees in a Grove or Wood grow 

 only in length, becaufe all the nourifhment 

 is by the leaves drawn to the top, mod of 

 the fmall lateral fhaded branches in the mean 

 time perifhing for want of pcrfpiration and 

 nutrition ,• fo the cafe is the very fame in the 

 branches of a tree, which ufually making 

 an angle of about 45 degrees with the flem 

 of the tree, do thereby beautifully fill up at 

 equal and proper diftances the fpace between 

 the lower branches, and the top of the tree, 

 forming thereby as it were a parabolical 

 Grove, or Thicket; which fhading the arms, 

 the fmall lateral fhoots of thofe arms ufually 

 perifh for want of due perfpiration 5 and 



therefore the arms continue naked like the 



bodies 



