4 2 



THE LEAF 



shown in Figures 73 and 74, illustrating the two modes of 

 arrangement. Label the point at which the leaf is in- 



7i 7 2 73 74 



71-74. Arrangement of leaves: 71, opposite-leaved twig of spindle tree; 

 72, alternate-leaved twig of apple; 73, vertical diagram of opposite-leaved twig; 



74, vertical diagram of two-ranked twig of elm. (71, 72, after GRAY.) ' 



serted, the node ; the space between any leaf and the one 

 next above or below it, the internode ; and angle between 

 the leaf and the stem, where you 

 see the bud, the axil. How many 

 leaves are there at a node in the 

 elm and basswood ? How many in 

 the maple and honeysuckle? Are 

 the two consecutive pairs of leaves 

 in the latter placed directly over 

 each other, or at right angles ? How 



75. Horizontal diagram of far round from the first leaf does 



opposite leaves. 



the second stand in the elm, grass, 



etc. ? How does its position differ 

 from that of the same leaf in the 

 opposite mode of insertion ? How 

 many leaves must be passed in order 

 to complete a turn round the stem, and 

 what leaf in numerical order stands 

 directly above the first ? Draw a hori- 



, ,. 76. Horizontal diagram 



zontal diagram of both twigs repre- of two-ranked leaves. 



