MIGRATIONS OF PLANTS 
bear winged seeds, which are so efficient in 
riding the breeze that they are really miniature 
aeroplanes. ‘The double wings of the Maple 
are very much like those of an insect. The 
seeds are released from their container in such 
manner as to acquire a whirling motion as they 
fall. 
The progeny of the Willow is provided with 
long projecting hairs which curl together to 
form a tiny balloon. fFeathery attachments 
called pappus enable the children of the Dan- 
delion, the Thistle and the Fire Weed to go on 
long jaunts of exploration. 
The seed-pods of the Sycamore are great rol- 
lers. Even ordinary nuts and fruits may be 
blown to considerable distances by the strong 
winds of autumn. The many edible seeds and 
fruits are carried gratis by birds and animals. 
The Mistletoe, for instance, is distributed en- 
tirely by them. 
Walnuts, Butternuts, and Acorns bear 
water travel well, as do certain of the hard 
seeds. The Arrowhead (Sagittaria) has a 
self-made water-wing on which its offspring 
float. 
[47] 
