70 
PLANTS AND INSECTS 
spring, becomes dry and of a brownish color. Where the white fragrant 
blossoms were are the round, oblong seed-pods. The trunk consists 
of a soft, spongy substance (pith) covered with about an eighth of an 
inch of hard shell; consequently it is very light. When about nine feet 
of the trunk of this plant was cut off, my two little nephews could 
easily carry it on their shoulders. 
One veiy interesting fact about the yucca is that it depends for 
the most important thing of all—its seed-production—on a tiny moth 
no longer than your finger-nail. Since the plant keeps its anthers, on 
which the pollen grows, away from its stigma, it renders the flowers 
incapable of self-pollination. The moth herself does not need food, but 
she knows that when her eggs hatch, her little larvae will be very hungry 
and that the only food they can live on is the yucca-seed. But she seems 
to know something much more wonderful than this—that the yucca 
will not produce seed unless the pollen reaches the stigma. At any 
rate, she acts as if she knew. This is what she does: Before laying 
her eggs she gathers a mass of pollen larger than her own head; next 
she lays her eggs in the ovary of the flower; and then she immediately 
crams the pollen down the concave stigma of this flower. So the big 
yucca can trust to the mother instinct of this tiny creature. True, her 
babies eat part of the seeds, but there are quite enough left to keep up 
the supply of yucca-plants. 
This picture was taken from a large yucca that grew in Pacoima 
Canyon, about twenty miles from Los Angeles. 
—Annabel Lee Hunnex. 
INTERESTING FACTS ABOUT NUTS 
A MONG the many nuts that come pattering to the earth in autumn, 
we find walnuts, chestnuts, hazelnuts, butternuts, hickory-nuts, 
and pecans. 
The name “walnut” means foreign nut, so called because the nut 
was first brought from Italy and France. There are about ten species 
of this nut, but we are most familiar with the persian, or English, wal¬ 
nut and the black, or common, American walnut. The English walnut 
is cultivated extensively in southern California, The tree grows to a 
height of sixty to ninety feet, and has large, spreading branches. The 
