244 
THE FRUIT 
233) and as it crawls about, its body becomes covered with 
pollen which is carried from flower to flower. Only the 
summer and fall flowers of caprifig produce pollen, and only 
the fall caprifig matures pollen at the time when the Smyrna 
figs are in blossom. The fig-wasp, seeking suitable flowers 
in which to deposit eggs, enters the Smyrna fig and leaves 
pollen from the flowers of caprifigs on the stigmas, thus 
fertilizing the Smyrna fig flowers which can now develop. 
It took many years of experimentation to discover all 
these intricate relations existing between the wild and the 
cultivated fig, and their dependence 
upon a certain insect to carry pollen. 
This is an extreme illustration of the 
interrelation between two closely re¬ 
lated plants and a parasitic insect. 
All these peculiar relations, how¬ 
ever, had to be worked out by scien¬ 
tists before the fig industry could 
become a success in California. Now 
Smyrna fig trees, wild caprifigs, and 
the fig-wasp have all been introduced, 
with the result that California’s fig¬ 
raising industry is a success. 
215. The Uses of Fruits to Man. — In speaking of the uses 
of fruits to man, it must be remembered that all the grains 
are fruits and that many so-called vegetables are fruits, 
as the tomato, the squash, and the cucumber. 
The most valuable source of food in the world is found 
in the cereals: wheat, oats, rye, rice, barley, and others. 
Nearly half of the population of the globe depends on rice 
for its principal food. Rice is the only one of the cereals 
that is commonly eaten entire. The others are usually 
ground and made into bread. The importance of bread as 
an article of food is shown by the term, “ the staff of life,” 
which is often applied to it. In the famine-stricken regions 
