INTRODUCTION 
. THE GROUND-PLANS OF NATURE 
Science is a collection of facts concerning natural objects or phenomena, arranged in good 
order, and made useful. 
Natural Science is the study of Nature’s works and forces, and embraces all things not made 
by man. Among its grand divisions may be mentioned natural history, chemistry, and physics. 
Natural History is the study of Nature’s common objects; but by most persons, this name 
is applied only to the study of animal life. Natural history treats of three great kingdoms — the 
animal, vegetable, and mineral. 
The Animal Kingdom embraces not only all the living creatures which now inhabit the earth, 
but also those which have died, become extinct, and left only their buried remains, called fossils. 
Of the animal kingdom, three great groups of subjects may be recognized, as follows: 
MAN, the study of whom is called An-thro-pol'o-gy 
THE LOWER ANIMALS, the study of which is called Zo-ol'o-gy 
EXTINCT, or FOSSIL ANIMALS, the study of which is called Pa-le-on-tol'o-gy 
In strict reality, Paleontology is only a branch of Zoology, for the two are inseparably dove- 
tailed together. The living animals of to-day are the standards by which the paleontologist 
studies and determines those of the past. 
This diagram illustrates the relations which the grand divisions of Natural History bear toward 
each other: 
Kingdoms. 
1 Animal: . 
Vegetable: 
Mineral: . 
Sciences. 
f An-thro-pol'o-gy 
Zo-ol'o-gy 
( Pa-le-on-tol'o-gy 
S Botany 
) Pa-le-o-bot'a-ny 
\ Ge-ol'o-gy 
l Min-er-al'o-gy 
In its broadest sense, Natural History includes Chemistry and Physics; but a,s that term is 
now commonly used, it is intended to refer only to the life histories of living creatures. 
An Animal is a living creature belonging to the animal kingdom ; but this word is commonly, 
though incorrectly, used to designate mammals alone. 
The animals of the world are so vast in number, and so varied in form, that these lessons will 
treat only of the higher forms of life, known as Ver'te-brates. 
A Vertebrate is an animal having (usually) a bony skeleton, and a spinal column, or back- 
bone, composed of a series of bones called ver'te-brae. This division of life is called a Branch. 
The Branch Ver-te-hra'ta is divided into seven grand divisions, called Classes; which are 
known as Mam'mals, Birds, Reptiles, Am-phib'ians, Fishes, My'zonts, and Lance'lets. 1 
1 Two other Classes, Enteropneusts and Tunicates, are, by some modern zoologists, regarded as 
Vertebrates. These low forms, however, lack a complete backbone, or notochord, and are therefore 
omitted. 
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