90 A TEXTBOOK OF GENERAL BOTANY 
The staghorn fern is a well-known example (Fig. 85). This 
plant has two types of leaves: ordinary foliage leaves which hang 


growing on a coconut trunk. (x 74 

down, and collecting 
leaves which - sur- 
round the mass of 
‘roots. 
Water collects in 
the cups formed by 
the overlapping lower 
portions of the leaves 
of some bromeliads 
and is absorbed by 
the leaves (Fig. 490). 
Protection. At the 
tip of a growing stem 
there is a soft, grow- 
ing region which is 
surrounded and pro- 
tected by the young 
leaves. This protec- 
tion may be afforded 
by whole leaves or 
by stipules (Figs. 15, 
86). Aside from this 
protective function 
many leaves are spe- 
cially modified for 
protecting the plant. 
The different kinds 
of leaves which have 
this special function 
may be divided into 
three classes: spiny leaves, motile leaves, and bud scales. 
Spiny leaves. A large number of animals feed directly on 
plants. In some cases this is of advantage to the plants, as when 
birds eat the fruits of a plant and scatter the seeds: but the 

