MANUAL, OF NATURE STUDY. 
123 
not adapted for willow growth, are swept bare of 
these seeds by the wind. The silky hairs are 
peculiarly adapted for clinging to the mud, spread¬ 
ing out and thus bringing the seeds into close con¬ 
tact with the mud for germination. Notice the 
maple seed with its butterfly wings, the linden with 
its skiff, the roundness of walnuts for rolling down 
hill, the roughness and wartiness of some seeds to 
hold the dirt well, the mucilaginous coating of the 
sun flower seeds and gourd seeds, when fresh, to 
enable them to adhere well to the soil. 
2. Show how seeds separate from plants. 
a. Fruits that do not open at maturity, fall by 
the force of gravitation, when the sap ceases to 
bring food from the leaves, but they fall mos 
rapidly during windy weather. Why is that true 
and of what advantage to the seed? Name as 
many fruits as are known to separate in this way. 
In this collection, apples, peaches, plums, pears, 
cherries, berries of every description, of course will 
be mentioned, together with some discussion as to 
the wisdom of nature in providing the juicy pulp 
and colored skin; but the fruits equipped with hairs, 
curved bristles or hooked spines, together with the 
winged fruits and plumes should have a prominent 
place in the discussion. 
b. Fruits that open and discharge their seeds 
when ripe. 
