8 INTRODUCTION. 
divide nature into three kingdoms, that of minerals, of plants, and 
of animals. 
_ As the history of mankind does not result from a collection of 
biographies, so Natural History is not formed by the description of 
animal species. Therefore Zoology describes not merely the sepa- 
rate animals (monographically) according to external parts and 
internal structure, but it comprises the entire kmgdom of animals, 
denotes their mutual relations, and assigns to each animal its rank 
and position. 
Zoology falls into different parts. First, it is divided into 
Description and History. Description of animals (zoographia) sup- 
plies precise descriptions of the separate internal and external parts 
of the animal body, and thus of the entire animal. In a narrower 
sense, it makes us acquainted with the external parts and the ex- 
ternal form of the animal, and with the distribution into classes 
and orders. When it makes us acquainted with the internal struc- 
ture of animals, as well in respect of form and position (structura) 
as of tissue (textwra), itis called the Anatomy of Animals (Zootomia), 
which has been especially cultivated of late years, and is generally 
named Comparative Anatomy (Anatomia Comparata). But this ap- 
pellation has not exactly the same meaning as the first: it denotes, 
rather, a philosophical science, which, not content with the simple 
knowledge of the different forms, investigates, by comparison of the 
anatomy of all animals and also of the human body, the general 
laws of animal organisation and its unity. 
The History of Animals (Historia Animalium) comprehends a 
comparative history of the nature and intellect of animals: it illus- 
trates the phenomena of life, and their obedience to law in the 
animal economy. It may be also termed General Physiology 
(Biology). The knowledge of the geographical and physical dis- 
tribution of animals over the surface of the earth, the knowledge 
of the series of forms which in earlier periods inhabited our planet, 
and of which the remains have been found in beds and strata of 
rocks deposited from water, also belong to the History of the Ani- 
mal Kingdom. 
These subdivisions cannot dispense with mutual assistance. 
Conjointly they form only one science which we term Zoology. 
