No. 383.] DISPERSION OF SEEDS AND FRUITS. 863 
The lighter and smaller the seeds, and the more there are of 
them, the better their chances for distribution, especially for 
long distances. The minute size of spores of most of the 
fungi are given as a reason why so many of them are so widely 
distributed. Why is a boy or man of light weight secured to 
ride the horse on the race track? That the animal may have 
less weight to carry, and thereby use his surplus strength in 
making better time. The less weight the parachute of the 
seed of the willow-herb has to carry, the greater the chances 
for success in making a long journey. Of the willow-herb, it 
takes one hundred seeds to weigh a milligram, including the 
hairs attached to them, and it would take thirty thousand to 
weigh as much as an ordinary white bean. 
Ripened pods of Lilium superbum usually stand straight up 
on a stiff elastic stem; beginning at the top, each one slowly 
splits, and the three parts separate from each other. Why do 
they not burst open all of a sudden, like pea pods, and shoot 
the seeds all about, and have the job done with? Or why does 
not the pod burst open at the lower end first instead of the 
upper? Observe that the coverings of the cavities are lashed 
together loosely with a latticework. No slight breeze can 
dislodge the seeds, but just see how they behave in a gale! 
The elastic stems are swayed back and forth against each 
other, and some of the upper seeds are tossed out by the wind 
which passes through the lattice, and at such times are carried 
forward. The seeds at the top having escaped, the dry pods 
split down farther and still farther, and open still wider, till 
the bottom is reached. Succeeding breezes may come from 
different directions, and, as the seeds are not all carried away 
the first, or even the second time, there are some left to be 
scattered about. 
The seeds of the lily are flat and rather light, not to be shot 
out like bullets, but to be carried a little way by the wind; the 
pods are erect and open at the top, that they need not escape 
when there is no wind unless some animal gives the stem a 
strong shake. I mention this plant on purpose to call your 
attention to the admirable scheme for economizing the supply 
of seeds. The latticework was made for a purpose, and the 
