3851

Protococcus

surface of the prothallus also appear in due
course the sexual reproductive organ?—the
antheridia Cmale) and archcjronia 'female';.

Protococcus, a £enus of sinple-celled Al-
ga often forming a yellowish-green stratum
on trees, damp walls, and shallow pools.

Protocol, originally the first leaf glued on
to a manuscript to show under whose direc-
tion and by whom the work was written.
Later the word was used to denote docu-
ments drawn up by notaries. In diplomacy,
a protocol is the preliminary draft intended
to serve as a basis for a subsequent treaty,
or the minutes of a congress or conference
recording an agreement to attain certain j
ends by peaceful means. In industry the term j
protocol is sometimes used of agreements be- j
tween employers and employees for the peace-
ful adjustment of labor problems.

Protogine, a modified form of granite
which has taken on the characters of gneiss
In the course of metamorphism accompanying
mountain making. The term is used especially
of the rock composing the central axis of the
Swiss Alps.

Protophyta, a collective name given in some
classifications to the simplest single-celled
plants. With the Protozoa, animals of equ-
ally simple structure, they make up the Pro-
tista of Haeckel.

Protoplasm, the physical basis of life, most
familiar as the jelly-like substance in certain
cells. In its simplest known state, cytoplasm,
it appears to be a homogeneous, transparent,
semi-fluid substance; but high magnification
and the use of suitable staining materials re-
veal a complicated structure. This appears to
differ in different cells and at different times,
but in general it is fibrillar — interspersed
with minute filaments of denser material;
reticular—with a mesh-work of delicate
threads; granular—with exceedingly minute
particles scattered in the substance; or alve-
olar—with a foam-like structure of liquid
containing vacuoles round which the proto-
plasm streams, Protoplasm is continually un-
dergoing chemical change, in the course of
which complex substances are built up from
simple ones, and are then in their turn broken
up, the whole series of changes constituting
what is known as metabolism.

Protozoa, or primitive animals, are typi-
cally unicellular organisms, in which the
whole organism takes part in the reproduc-
tive process. Not a few Protozoa consist of a
colony of cells, but generally in such colonies
the units are more or less physiologically
complete, each being usually capable of car-

Proust

ryins: on all the animal functions, including
that of reproduction. The Protozoa are thus
contrasted with the Melazoa, in which the
organism consists of many cells, arranged in
at least two layers, which have different
physiological functions. Protozoa may be di-
vided into three classes: The Rhizopoda, in-
cluding forms generally resembling Amoeba,
whose locomotor organs are pseudopodia; the
Infusoria, or forms which progress by ac-
tively moving threads, either of the type of
flagellse, as in the Flagellata, or of cilia, as
in the Ciliata; the Sporozoa, which in the
adult stage have no definite locomotor proc-
esses, are parasitic in habit, and reproduce by
means of spores.

Protractor, a drawing instrument for lay-
ing off angles. It is usually in the form of a
circle, semicircle, or quadrant, graduated
alonr: the margin into degrees, the central
point being indicated by a mark or hole.
Protractors may also be constructed on or-
dinary straight divided scales if these are
broad enough.

Proud, Robert (1728-1813), American his-
torian, born in Yorkshire, England. He emi-
grated to Pennsylvania in 1759, and taught
in Philadelphia until the outbreak of the
Revolution. His History of Pennsylvania (2
vols., Phila., 1797-8) is still valuable for the
period it covers, from 1681 to 1742.

Proud Flesh, the popular term for exub-
erant granulations of ulcers or wounds. The
new formed cells, which should lie at the
level of the skin about the ulcer, and be of
a bright-red color, in proud flesh rise above
the common level, and are more or less pale
and watery in appearance. They are, in fact,
redundant and weakly. The proud flesh
should be treated with dry dressings, and, if
necessary, rubbed freely with sulphate of
copper (blue stone) or sulphate of zinc.

Proudhon, Joseph (1809-65), French so-
cialist, born at Besangon. He first became fa-
mous by his tract (1840), What is Property?
He was a dreaded critic of the dominant
bourgeois party, and spent a considerable
time in prison. He framed no system and es-
tablished no doctrine; but he regarded the
constant appeal to the state for assistance
as the bane of French political and social
life. His few followers called themselves mu-
tualists, and their idea is that society ought
to rest on a basis of equality and of recip-
rocity of service rendered.

Proust, Joseph Louis (1755-1826),
French chemist, was born at Angers. His work
was characterized by its great exactitude, and