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. Sciences. 



( An-thro-pol'o-gy 



Animal : < Zo-ol'o-gy 



( Pa-le-on-tol'o-gy 

 NATURAL HISTORY / i Botany 



(in a broad sense). ^ Vegetable: \ Pa-le-o-bot'a-ny 



Mineral- \ Ge - ol '°-gy 



mineral j Min-er-al'o-gy 



In its broadest sense, Natural History includes Chemistry and Physics; but as 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-bra'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. 



