the Science of Botany. 33 



is divided into four orders, which confift in 

 the diredlion, the place, the infertion, and the 

 fituation. 



I. The direflion, fee fig. 16. is the expan- 

 fion which the leaf requires from the bottom 

 to the top. If it is arched [inflexiun), that is, 

 when it returns toward the footftalk, as at ^, ^ ; 

 when it is upright [ereBum)^ that is, if it 

 makes an acute angle with the footftalk, fee 

 bi b. If it fpreads open, or ftands almoftina 

 right angle with the perpendicular c, r, it is 

 called [patens) 5 when it is horizontal, that is, 

 when it makes a right angle with the perpen- 

 dicular, as at ^, J, {Jjorizo7itale) ; when the leaf 

 is reclinated, or the fummit is turned fo that it 

 is lower than the bafe [rechnatum)^ as at ^, e y 

 when it is turned back, or rolled, as at y, f^ 

 {revoIutum)y or a revolved leaf. 



When a leaf puts out a radicle from its top, 

 asfome of the ferns do, it is called radicans-^ 

 if it puts out roots from its under furface, 

 radicatum ; and if they float on the water, 

 iiatans, 



II. The place, fee fig. 17. this is determined 

 by the place where it is fattened to the plant; 

 the feed leaf ([eminale)^ a, a, is that which is 

 firft put out from the feed, and is often called 

 CQtykdon, or Seed-leaf, 



c A- 



