ZOOLOGY. 



569 



D. ORDERS AND FAMILIES. 



3456. Had the names been given in strict accordance 

 with rank ; then the class-divisions, which correspond to 

 the circles, would have been called Orders. 



3457. Families would be class-divisions, which corre- 

 spond to the classes themselves. 



3458. In no class therefore could there be more than 

 four orders admitted, or five, if the sensorial organs be 

 reckoned to constitute a special circle. 



From the same reason there are no more than thirteen 

 or seventeen families. These names cannot meanwhile be 

 so strictly adopted, because the classes are not of equal 

 rank, as has been observed ; on this account it is neces- 

 sary to shove in here and there other divisions, which 

 should be termed at one time Cohorts, at another, Alli- 

 ances. 



3459. If the animals of a class differ from each other, 

 it is only possible by their bringing to bear in addition 

 to their characteristic organ some other organ, and con- 

 sequently becoming similar to an earlier or later class. 



3460. Yet nevertheless in this ascent the animals 

 could never outstep the confines of their own circle. 

 There can be no Dermatozoon which could have bones ; 

 for in that case it would be an Osteozoon, and belong to 

 another province. 



Every class therefore comprises as many orders only as 

 there are circles with which it comes into contact. Thus 

 in the first circle there is only one order, in the second 

 two, and so on. 



Each class therefore includes also as many families 

 only as the circles which are touched by it contain classes. 

 Thus the first to the third class has three, the fourth to 

 the sixth, six ; the seventh to the ninth, nine ; the tenth 

 and so on, thirteen. 



3461. The serial arrangement of animals into families 

 is naturally difficult ; but in Physio-philosophy we have 

 to treat not about the execution of the Systematic in 

 detail, but concerning its principles. 



