The Life of Plants 
seed is small, with a sharp point, and stiff, short hairs pointing 
backwards. The upper end of the seed is produced into a fine twisted 
corkscrew-like rod, which is followed by a plam cylindrical portion, 
attached at an angle to the corkscrew, and ending in a long and 
beautiful feather, the whole being more than a foot in length. The 
long feather, no doubt, facilitates the dispersion of the seeds by wind; 
eventually, however, they sink to the ground, which they tend to 
reach, the seed being the heaviest portion, pomt downwards. So the 
seed remains as long as the weather is dry, but if a shower comes 
on, or when the dew falls, the spiral unwinds, and if, as is most 
probable, the surrounding herbage or any other obstacle prevents the 
feathers from rising, the seed itself is forced down and so driven by 
degrees into the ground, or if 
the wind rises it catches the 
feather and twists the seed into 
the ground like a corkscrew. 
I have not space to discuss 
the roots or stem, but should 
like to say a few words about 
leaves. Weall know the endless variety they present, 
and we may be sure that there is some cause and 
explanation for every one of these differences. There 
are many 
interesting 
problems 
in this 
field. Let 
me just 
give you 
one or two 
illus tra- 
tions. 
v SYCAM ORE. Take for 
a 
Pay? 
Fig. 6. 
instance 
the beech 
(Fig. 8). The sails of a ship must be propor- 
tionate to the strength of the masts that carry 
them. So also the strength of the branches 
determines the leaf area. In our trees the leaves 
are arranged so as to get as much light and heat 
as possible. In hot dry countries they are often 
arranged so, as to cover and protect one another, 
in some of the New Zealand veronicas for instance. 
With us it is the reverse. Hence the width of 
the beech leaf is determined by the distance 
between the buds—if they were narrower space Se 
would be wasted; if they were wider they would aN 
overlap. The size and width being thus arrived Ss 
at the length is also determimed—if they were of 
. shorter they would be too small, if they were ~— ————— 
longer they would overweight the branches. sD Uh 
