FAMILY CHARACTERISTICS 109 



CHAPTER VIII. 



FAMILY CHARACTERISTICS. 



Let us proceed to a careful examination of 

 the natural groups of animals called Families 

 by naturalists, — a subject already briefly alluded 

 to in a previous chapter. Families are natu- 

 ral assemblages of animals less extensive than 

 Orders, but, like Orders, Classes, and Branches, 

 fou nded upon certain categories of structure, 

 as distinct for this kind of group as are those 

 above specified for the other divisions in the 

 classification of the Animal Kingdom, which we 

 have thus far examined. 



That we may understand the true meaning 

 of these divisions, we must not be misled by the 

 name given by naturalists to this kind of groups. 

 Here, as in so many other instances, a word 

 already familiar, and as it were identified with 

 the special sense in which it had been used, 

 was adopted by science, and received a new sig- 

 nification. When naturalists speak of Families 

 among animals, they do not allude to the proge- 

 uy of a known stock, as we designate, in com- 



