134 FOUNDATIONS OF BOTANY 
142. The Maple Leaf. — Sketch the leafy twig. 
Are the leaves arranged in rows like those of the elm? How are 
they arranged? 
How are the petioles distorted from their natural positions to 
bring the proper surface of the leaf upward toward the light? 
Do the edges of these leaves show larger spaces between them 
than the elm leaves did, z.e., would a spray of maple intercept the 
sunlight more or less perfectly than a spray of 
elm? Pull off a single leaf and sketch its lower 
surface, about natural size. 
Of the two main parts whose names have 
already been learned (blade and petiole), which 
is more developed in the maple than in the 
elm leaf? 
Describe : 
(a) The shape of the maple leaf as a whole. 
To settle this, place the leaf on paper, mark the 
positions of the extreme points and connect 
a oe oe these by a smooth line. 
Galandina: (6) Its outline as to main divisions: of what 
The blade of theleafis kind and how many. 
discontinuous, con- (c) The detailed outline of the margin 
sisting of several por- , 
tions between which (Fig. 93). et 
are spaces in which Compare the mode of veining or venation of 
one part of the blade the elm and the maple leaf by making a 
has been developed. 2 
diagram of each. 
These leaves agree in being netted-veined ; i.e., in having veinlets 
that join each other at many angles, so as to form a sort of delicate 
lace-work, like Figs. 94 and 95. 
They differ, however, in the arrangement of the principal veins. Such 
a leaf as that of the elm is said to be feather-veined, or pinnately veined. 
The maple leaf, or any leaf with closely similar venation, is said to 
be palmately veined. Describe the difference between the two plans 
of venation. 
143. Relation of Venation to Shape of Leaves. — As soon 
as the student begins to observe leaves somewhat widely, 
