136 



-ways in an angular or circular posture, and their vas- 

 cular fibres or threads, are three, fire, or seven. The 

 reason of this position is, for the more erect growth, 

 and for the greater strength of the leaf, as also for the 

 security* of its sap. 2. The accurate position of these 

 fibres, which often take hi the eighth part of a circle, 

 as in mallows ; in some plants a tenth, but in most a 

 twelfth, 3. The art in folding up the leaves before 

 the eruption is incomparable both for elegance and se- 

 curity. They take up the least room their form will 

 bear, and are so conveniently couched as to be capable 

 of receiving protection from other parts, and of giving 

 It to each other. 



Leaves consist of fibres continued from the trunk of 

 the tree. They are clothed with an extremely thin 

 pellicle which is covered with the finest down. Their 

 skin or coat is only that of the branches extended, as 

 gold is by beating. In the bud they arc folded up al- 

 most in the manner of a fan, sometimes in two, some, 

 times in several plaits ; but if they are too thick to 

 plait commodiously in two, and to be ranged agaiust 

 each other, or if they are too small a number, or their 

 fibres too delicate, instead of being plaited, they are 

 rolled up, and form either a single roll or two rolls, 

 which begin at each extremity of the leaf, and meet in 

 the middle: there are also some plants, as fern in par. 

 ticular, which form three rolls. 



The chipf use of leaves seem to be, 1. To catch the 

 dew and rain, and so convey more nourishment to the 

 plant than the root alone could do. < 2. To take ia 

 air (of which more hereafter) and 3. To minister to a 

 kind of insensible perspiration, by which redundancies 

 may be thrown oif. 



9. The Nutrition of plants seems to be performed 

 thus* As the earth abounds with particles of every 

 sort, those which suit each plant being dissolved by 

 moisture and agitated by heat, enter the root through 

 its threads or pores, ascend through the woody fibres, 

 and being in the resides of the plant mixed with its 



