28 Classification of the Animal Kingdom. 



access to much more extensive libraries thau can be found in this country. 



The fossils of Canada are for the greater part of extinct species, and ia 

 most cases of extinct genera. In order to explain clearly what this means, 

 we shall refer again to our friends the bears. If by some fatality all the 

 black bears should perish, then the species would become extinct — ages might 

 roll away, but Ursus Americanus would never once be seen in life. If all 

 the individuals of every species of Ursus should perish, then the genus would 

 be extinct. In the British Museum there are preserved the remains of several 

 extinct species of Ursus. There is the Ursus spelczus, or Cave Bear, 

 whose bones have been found in the ancient caves of several European coun- 

 tries, and the Ursus priscus, or the first of all bears. Xone of these are 

 at present in existence, and their species are therefore extinct, but the genua 

 still survives, and is represented by eight or ten well known and clearly de- 

 fined species besides several varieties in various parts of the world. 



Ou the other hand, Ichthyosaurus, Plesiosaurus, and others, whose 

 figures may be seen in many of the common school books, are examples of 

 extinct genera. 



No progress of any value can be made in the study of Natural History 

 without attention to the distinction between genus and species, and to the 

 principles of classification, and we shall therefore quote in this place the re- 

 marks of Messrs. Agassiz & Gould, in their recent work upon this subject. 



'■• Every art and science has a language of technical terms peculiar to 

 itself. With those terms the student must make himself familiarly acquain- 

 ted at the outset ; and first of all, he will desire to know the names of the 

 objects about which he is to be engaged. 



The names of objects in Natural History are double, that is to say, they 

 are composed of two terms. Thus, we speak of the white-bear, the black- 

 bear, the hen-hawk, the sparrow-hawk ; or, in strictly scientific terms, we 

 have Felis ho, the lion ; Felis tigris, the tiger ; Felis catus, the cat ; 

 Canis lupus, the wolf ; Canis vulpes, the fox ; Canis familiaris, the 

 dog, &c. They are always in the Latin form, and consequently the adjec- 

 tive name is placed last. The first is called the generic name ; the second 

 is called the trivial, or specific name. 



These two terms are inseparably associated with every object of which 

 we treat. It is very important, therefore, to have a clear idea of what is 

 meant by the terms genus and species ; and although the most common of 

 all others, they are not the easiest to be clearly understood. The Genus is 

 founded upon some of the minor peculiarities of anatomical structure, such 

 as the number, disposition, or proportions of the teeth, claws, fins, &c., and 

 usually includes several kinds. Thus, the lion, tiger, leopord, cat, &c., agree 

 in the structure of the feet, claws, and teeth, and they belong to the genus 

 Felis ; while the dog, fox, jackall, wolf, &c., have another and a diflerent 

 peculiarity of the feet, claws, and teeth, and are arranged in the genus Canis. 



The species is founded upon less important distinctions, such as colour , 

 size, proportions, sculpture, «fec. Thus we have diflerent kinds, or species, of 

 duck, different species of squirrel, diflerent species of monkey, &c., varying 



