As the fruit
becomes developed, the pellicle thins, becomes transparent, and allows
both light and heat to exercise a more marked influence. It is during
this period that maturation commences. The acids react on the cambium,
which flows into the fruit, and, aided by the increased temperature,
convert it into saccharine matter; at the same time they disappear,
being saturated with gelatine, when maturation is complete.--_London
Medical and Surgical Journal_.
We may here observe that in a recent paper, by Mr. J. Williams, in the
Transactions of the Horticultural Society, the cause of apples becoming
_russet_ is attributed to the alternating temperature, light, shade,
dryness, and moisture, which occur many times in the course of a day,
when July or August is showery. Continued rain, preceded and followed by
a cloudy sky, does not seem to produce the same effect, but the sudden,
intense light which commonly succeeds a shower at the time the fruit is
wet, injures the skin, and occasions small cracks, like the network upon
a melon.
* * * * *
MIGRATION OF BIRDS.
Whatever theory of instinct may be finally fixed upon as the most
correct and philosophical, (to account for the migratory movements of
birds,) it is obvious that we cut rather than untie the gordian knot
when we talk of the foresight of the brute creation.
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