862 THE AMERICAN NATURALIST. [Vou. XXXII. 
breeze tears off a few pods, and they fall on the snow, which 
has filled up all the crevices in the grass and between the 
dead leaves and rubbish. Each half pod freighted with 
seed is admirably constructed, like an ice boat, with sail 
always to the breeze. In this way there is often nothing to 
hinder some of the seeds from going a mile or two in a few 
minutes, now and then striking some object which jars off a 
seed or two. The seeds are very hard, and no doubt purposely 
so, that they may be seldom eaten by insects or birds ; but once 
in moist, soil, the covering slowly swells and decays, allowing 
the young plant to escape. Thus the locust seeds are provided 
with neither legs, wings, fins, nor do they advertise by brilliant 
hue and sweet pulp, but they travel in a way of their own, and 
literally on the wings of the wind. 
On lowlands, more or less abundant throughout the Northern 
Temperate Zone, is found the great willow-herb, Zpzlobzum 
angustifolium. When ripe the slender pod slowly recurves 
from the top into four pieces and exposes the very small seeds, 
each having at one end a tuft of fine, white, silky hairs nearly 
half an inch long. Almost every one would think the seeds 
grew in this manner to be scattered by the wind, and no doubt 
this is correct. I call your attention to the plant for the pur- 
pose of showing that the tips of the hairs stick slightly to 
grooves inside of the recurved valves, some hairs to one valve, 
and often others to the adjacent valve, thus spreading them 
apart with the seed suspended Between. Four rows of the 
seeds are thus held out at oné time. Not over half to a 
tenth part of the seeds are well developed, yet the silky hairs 
are present and float away in clusters, helping to buoy those 
that are heavy. This is a capital device, and when dry and 
unfurled, it silently indicates to the slightest breath of air that 
the seeds are ready for a flight, and it does not take much to 
carry them a long distance. 
Do you know why so many kinds of plants produce very 
small and light seeds? Would it not be better if they produced 
fewer and larger seeds which would be stronger and better able 
to grow under adverse conditions? But many small seeds cost 
the plant no more effort than a small number of large ones. 
