Chapter I: Front Matter

Transcriber's notes:

(1) Numbers following letters (without space) like C2 were originally
printed in subscript. Letter subscripts are preceded by an
underscore, like C_n.

(2) Characters following a carat (^) were printed in superscript.

(3) Side-notes were relocated to function as titles of their respective
paragraphs.

(4) Macrons and breves above letters and dots below letters were not
inserted.

(5) [root] stands for the root symbol; [alpha], [beta], etc. for greek
letters.

(6) The following typographical errors have been corrected:

ARTICLE ICHTHYOLOGY: "Within it in Neoceratodus are a number of
longitudinal rows of pocket valves." 'longitudinal' amended from
'longtitudinal'.

ARTICLE IDEALISM: "... the systems of impious and profane persons
which exclude all freedom, intelligence, and design from the
formation of things, and instead thereof make a self-existent ..."
'freedom' amended from 'freeedom'.

ARTICLE ILLINOIS: "An anti-trust law of 1893 exempted from the
definition of trust combinations those formed by producers of
agricultural products and live stock, but the United States Supreme
Court in 1902 declared the statute unconstitutional as class
legislation." 'United' amended from 'Untied'.

ARTICLE IMAM: "... Juynboll's De Mohammedanische Wet, 316 seq. ..."
'Mohammedanische' amended from 'Mohammedaanische'.

ENCYCLOPAEDIA BRITANNICA

A DICTIONARY OF ARTS, SCIENCES, LITERATURE
AND GENERAL INFORMATION

ELEVENTH EDITION

VOLUME XIV, SLICE III

Ichthyology to Independence

ARTICLES IN THIS SLICE:

ICHTHYOLOGY ILLUSTRES
ICHTHYOPHAGI ILLYRIA
ICHTHYOSAURUS ILMENAU
ICHTHYOSIS ILMENITE
ICKNIELD STREET ILOILO
ICON ILSENBURG
ICONIUM IMAGE
ICONOCLASTS IMAGE WORSHIP
ICONOSTASIS IMAGINATION
ICOSAHEDRON IMAM
ICTERUS IMBECILE
ICTINUS IMBREX
IDA IMBROS
IDAHO IMERETIA
IDAR IMIDAZOLES
IDAS IMITATION
IDDESLEIGH, STAFFORD NORTHCOTE IMITATION OF CHRIST, THE
IDEA IMMACULATE CONCEPTION, THE
IDEALISM IMMANENCE
IDELER, CHRISTIAN LUDWIG IMMANUEL BEN SOLOMON
IDENTIFICATION IMMERMANN, KARL LEBERECHT
IDEOGRAPH IMMERSION
IDIOBLAST IMMIGRATION
IDIOM IMMORTALITY
IDIOSYNCRASY IMMUNITY
IDOLATRY IMOLA
IDOMENEUS IMP
IDRIA IMPATIENS
IDRIALIN IMPEACHMENT
IDRISI IMPERIAL CHAMBER
IDUMAEA IMPERIAL CITIES OR TOWNS
IDUN IMPEY, SIR ELIJAH
IDYL IMPHAL
IFFLAND, AUGUST WILHELM IMPLEMENT
IGLAU IMPLUVIUM
IGLESIAS IMPOSITION
IGNATIEV, NICHOLAS PAVLOVICH IMPOST
IGNATIUS IMPOTENCE
IGNORAMUS IMPRESSIONISM
IGNORANCE IMPRESSMENT
IGNORANTINES IMPROMPTU
IGUALADA IMPROVISATORE
IGUANA IN-ANTIS
IGUANODON INAUDI, JACQUES
IGUVIUM INCANTATION
IJOLITE INCE, WILLIAM
IKI INCE-IN-MAKERFIELD
ILAGAN INCENDIARISM
ILCHESTER INCENSE
ÎLE-DE-FRANCE INCEST
ILETSK INCH
ILFELD INCHBALD, MRS ELIZABETH
ILFORD INCHIQUIN, MURROUGH O'BRIEN
ILFRACOMBE INCLEDON, CHARLES BENJAMIN
ILHAVO INCLINOMETER
ILI INCLOSURE
ILION IN COENA DOMINI
ILKESTON INCOME TAX
ILKLEY INCORPORATION
ILL INCUBATION and INCUBATORS
ILLAWARRA INCUBUS
ILLE-ET-VILAINE INCUMBENT
ILLEGITIMACY INCUNABULA
ILLER INDABA
ILLINOIS INDAZOLES
ILLORIN INDEMNITY
ILLUMINATED MSS. INDENE
ILLUMINATI INDENTURE
ILLUMINATION INDEPENDENCE
ILLUSTRATION

ICHTHYOLOGY (from Gr. [Greek: ichthys], fish, and [Greek: logos], doctrine or treatise), the branch of zoology which treats of the internal and external structure of fishes, their mode of life, and their distribution in space and time. According to the views now generally adopted, all those vertebrate animals are referred to the class of fishes which combine the following characteristics: they live in water, and by means of gills or branchiae breathe air dissolved in water; the heart consists of a single ventricle and single atrium; the limbs, if present, are modified into fins, supplemented by unpaired median fins; and the skin is either naked or covered with scales or with osseous plates or bucklers. With few exceptions fishes are oviparous. There are, however, not a few members of this class which show a modification of one or more of these characteristics, and which, nevertheless, cannot be separated from it.