LETTEES FEOM ALABAMA. 
175 
stalk. There is remarkable peculiarity in their 
manner of growth ; the young unexpanded leaves 
curiously folded up, grow within two large leaf- 
like bracte^, forming an oval sac, which, as the 
young leaf grows, swell, and at length burst, and 
TWIG OF TULIP-TREE. 
are left on each side of the leaf-stalk, as represented 
in the accompanying engraving. There is a suc- 
cession of these ; if we examine a young twig, per- 
haps we find two or three leaves {a a a) already 
expanded, and as many pairs of these bracts {bbh) 
