which are variously ciliated, and have the power of swimming, being known variously as the zoospores, swarm-spores, swimming spores, etc. Most of the forms also have sexual reproduction, producing a fertilized egg. Some of the forms are free-swimming; while most of them have means of anchoring themselves to firm supports. The main groups are as follows: Protococcus forms, which are one-celled and reproduce mostly by cell-division; Conferva forms, which are filamentous and produce swarm-spores as well as sexual spores; Siphon forms, as in the common green felt; and Conjugate forms, of which Spirogyra, the pond-scum is the best known. The last are called Conjugate forms because in the sexual process two filaments put out tubes toward one another, which meet and form a passageway, and through these improvised tubes the sex-cells pass. The name refers to this yoking together. It is from the green algæ that the higher plants are supposed to have come.
Chlorophyll (klō′rō-fĭl), the green
coloring matter of plants. It is found associated
.jpg)
FIG. I
with
protoplasm, usually in
special bodies
called chloroplasts
or
chlorophyll bodies,
which are found
only in cells near
the surface of
parts exposed to
light, e. g., in
leaves and twigs.
These are
usually rounded granules much too small to be
seen with the naked eye (see Fig. I). In
some algæ they are much larger, and have
curious shapes. Little is known with
certainty of the chemical nature of chlorophyll,
because it easily decomposes.
Besides the pure green coloring matter (to
which the name chlorophyll may be
restricted), yellow pigments (carotin or
xanthophyll) are associated with it in the
mosses, ferns and seed-plants. In some
algæ browns or blues or reds may be present
also. The green pigment particularly
(and in part the others) enables the plant
to absorb certain portions of the light. The
energy thus gained is partly used in the
making of new foods (see Photosynthesis).
In the absence of chlorophyll, this
work cannot be accomplished. Chlorophyll
is probably being continuously produced
and destroyed in green plants. It is not
usually formed in darkness, and if light
is excluded from a green plant the
destruction of the chlorophyll leaves it a
pale yellow. Autumnal colors are due
in part to the decomposition of the
chlorophyll.
.jpg)
Chloroplasts: (a) Position in cells. (b) Isolated.
Chloroplast (klō′rō̇-plăst), a protoplasmic body in plant cells that is stained by chlorophyll, and thus gives the characteristic green color to plants. For the work of chloroplasts see Photosynthesis.
Choate (chōt), Joseph Hodges, a talented
and eloquent lawyer, forceful public speaker
JOSEPH H. CHOATE
and United States
ambassador to
England, was born
at Salem, Mass.,
Jan. 24, 1832.
After graduating at
Harvard, he adopted
law as a
profession, and, joining
W. M. Evarts
in legal practice at
New York, he rose
quickly to
eminence, owing to his
high forensic abilities
and soundness
as a lawyer and
counselor. His chief exploits at the bar were
his defense of General Fitz-John Porter, when
court-martialed on a charge of disobeying
orders, and his vigorous campaign against
the corrupt Tweed ring in the city government
of New York. In 1894 he was chairman
of the convention held to revise the
constitution of the state of New York. He
also took part in the argument before the
supreme court of the United States as to the
validity of the provision as to income tax in
the tariff law of 1894, the court upholding
his contention that the income tax could not
be collected, but leaving the remainder of the
tariff law in force. Mr. Choate is a nephew
of the great Rufus Choate. He is noted as
a public and after-dinner speaker. In Jan.
