CLASSIFICATION. 



monkeys, hedgehogs, cats, whales, elephants, cows, anteaters, and 

 kangaroos ; a circumstance whereby they are distinguished from 

 birds, reptiles, or fishes. All animals that give suck are, there- 

 fore, associated to form one great class the Mammals. 



Or we may take the converse of all this. Thus, in the animal 

 kingdom there is a Class of creatures recognizable by the circum- 

 stance that they suckle their young ; among these is an Order, 

 distinguished by having chisel-like teeth in the front of their 

 mouths ; belonging to this Order is a Genus, remarkable for the 

 possession of a long tapering tail, and the smallest Species be- 

 longing to this genus is the harvest-mouse, Mns messorius. An 

 arrangement such as this enables us to find out the name of any 

 animal, and is called a system, which, in fact, is a dictionary, with 

 this difference, that here the properties enable us to find out the 

 name, whereas in ordinary dictionaries the known name serves 

 to acquaint us with the properties. Thus, the study of Zoology 

 is one eminently calculated to accustom the mind to habits of 

 order and precision, to a close and accurate comparison of objects 

 presented to our notice, and to a clear and neat perception of their 

 distinctive characters ; it gives a facility of expression to our de- 

 scriptions, and in this way its importance, as a branch of educa- 

 tion, can scarcely be exaggerated. 



Perhaps nothing has contributed so much to the advancement 

 of the science of Natural History as the happy expedient first 

 adopted by Linnaeus, of giving to every object in Nature a double 

 name, whereby its identity is at once satisfactorily indicated. 

 Thus, in the examples given above, we say Mus musculus, JMiis 

 rattns, filus messorius. The first of the two names is that of the 

 genus, and, therefore, common to all the species of that genus ; 

 the second is the specific name that is, points out the species 

 to which we refer, just in the same manner as in the names of 

 persons. The family name Milton or Shakspeare may belong to 

 anybody, but John Milton and William Shakspeare are indi- 

 viduals at once recognizable. The cnly difference is that in this 

 case the specific name is placed first, instead of after that of the 

 genus. To understand the importance of this great step in 

 zoological science, it is only necessary to read the descriptions 

 of old authors, who, after devoting half a page to the identifica- 

 tion of an animal, leave you in doubt whether they are speaking 

 of a cat, or a rat, or a hippopotamus. 



With regard to the classification of the immense series of living 

 beings composing the animal creation, various systems have been 



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