INTRODUCTION 



i. Definition of Zoology, and its Place among the 

 Sciences. The province of Natural History is to de- 

 scribe, compare, and classify natural objects. These 

 objects have been divided into the "organic" and -the 

 " inorganic," or those which are, and those which are 

 not, the products of life. Biology is the science of the 

 former, and Mineralogy the science of the latter. 

 Biology again separates into Botany, or the Natural 

 History of Plants, and Zoology, or the Natural History 

 of Animals ; while Mineralogy divides into Mineralogy 

 proper, the science of mineral species, and Lithology, 

 the science of mineral aggregates or rocks. Geology is 

 that comprehensive knowledge of the earth's structure 

 and development which rests on the whole doctrine of 

 Natural History. 



If we examine a piece of chalk, and determine its 

 physical and chemical characters, its mode of' occurrence 

 and its uses, so as to distinguish it from all other forms 

 of matter, we have its Mineralogy. But chalk occurs 

 in vast natural beds ; the examination of these masses 

 their origin, structure, position, and relation to other 

 rocks is the work of the Lithologist. Further, we 

 observe that while chalk and marble are chemically 

 alike, they widely differ in another respect. Grinding 

 a piece of chalk so thin that we can see through it, and 

 putting it under a microscope, we find imbedded in it 

 innumerable bodies, about the hundredth of an inch in 

 diameter, having a well-defined, symmetrical shape, and 

 chambered like a nautilus. We cannot say these are 



ii 



