THE LEAF 153 
Not only do leaves of different 
kinds exhibit these characteristics 
in varying degrees, but young and 
old leaves, or those on young and 
old plants of the same kind, often 
differ from each other in color, size, i 
shape, texture, mode of attachment, 198 199 200 201 202 
and the like, to such a degree (Figs. joaco" 198 const: 190, dene 
203, 204) that one not familiar tates 200, crenate; 201, undulate; 
with them in both stages would ee reer 
hardly recognize them as belonging to the same species. 
The young leaves 
of eucalyptus, mul- 
berry, and some oaks 
afford conspicuous 
examples of such 
differences, and they 
exist between the 
cotyledons and ma- 
ture leaves of most 
plants. 
Can you see any 
benefit, in the case 
of the plant whose 
leaves you are study- 
ing, that could be 
derived from such of 
203 204 ae 
the characteristics 
Fics. 203, 204.— Leaves of paper mulberry tree: 
203, leaf from an old tree; 204, leaf from a two-year- named above as 
old sprout. they may exhibit? 
Practical Questions - 
1. Tell the nature and use of the stipules in such of the following plants 
as you can find: tulip tree; fig; beech; apple; willow; pansy; garden 
pea; Japan quince (Pyrus Japonica); sycamore; rose; paper mulberry 
(Broussonetia). 
