, in fact, a secretion from protoplasm. Such is the rosy cheek
of an apple, or of a maiden, the luscious juice of the peach, the
produce of the castor-oil plant, the baleen that lines the whale's
enormous jaws, as well as that softest product, the fur of the
chinchilla. Indeed, every particle of protoplasm requires, in order
that it may live, a continuous process of exchange. It needs to be
continuously first built up by food, and then broken down by
discharging what is no longer needful for its healthy existence. Thus
the life of every organism is a life of almost incessant change, not
only in its being as a whole, but in that of all its protoplasmic
particles also.

[Illustration: FIG. 4. AMOEBA SHOWN IN TWO OF THE MANY IRREGULAR
SHAPES IT ASSUMES. _(After Howes_.)

The clear space within it is a contractile vesicle. The dark body is
the nucleus. In the right-hand figure there is shown a particle of
food, passing through the external surface.]

Prominent among such processes is that of an interchange of gases
between the living being and its environment. This process consists in
an absorption of oxygen and a giving-out of carbonic acid, which
exchange is termed respiration.

Lastly, protoplasm has a power of motion when appropriately acted on.
It will then contract or expand its shape by alternate protrusions and
retractions of parts of its substance. These movements are termed
amoebiform, because they quite resemble the movements of a small
animalcule which is named amoeba. (See Fig. 4.)

Such is the ultimate structure, and such are the fundamental
activities or functions of living organisms, as far as they can here
be described, from the lowest animalcule and unicellular plant, up to
the most complex organisms and the body of man himself.

[Illustration]

INHABITANTS OF MY POOL

(FROM MAGIC GLASSES.)

BY ARABELLA B. BUCKLEY.

The pool lies in a deep hollow among a group of rocks and boulders,
close to the entrance of the cove, which can only be entered at low
water; it does not measure more than two feet across, so that you can
step over it, if you take care not to slip on the masses of green and
brown seaweed growing over the rocks on its sides, as I have done many
a time when collecting specimens for our salt-water aquarium. I find
now the only way is to lie flat down on the rock, so that my hands and
eyes are free to observe and handle, and then, bringing my eye down to
the edge of the poo