STUDIES IN ANIMAL LIFE. 93 



same principles the monkeys being obviously dis- 

 tinguished from rodents, and the carnivora from 

 the ruminating animals ; and so of the rest. In each 

 order there are generally families, and the families 

 fall into genera, which differ from each other only 

 in fewer and less important characters. The genera 

 include groups which have still fewer differences, 

 and are called species; and these, again, include 

 groups which have only minute and unimportant 

 differences of color, size, and the like, and are call- 

 ed sub-species, or varieties. 



"Whoever looks at the immensity of the animal 

 kingdom, and observes how intelligibly and system- 

 atically it is arranged in these various divisions, 

 will admit that, however imperfect, the scheme is a 

 magnificent product of human ingenuity and labor. 

 It is not an arbitrary arrangement, like the group- 

 ing of the stars in constellations; it expresses, 

 though obscurely, the real order of Nature. All 

 true classification should be to forms what laws are 

 to phenomena; the one reducing varieties to sys- 

 tematic order, as the other reduces phenomena to 

 their relation of sequence. Now if it be true that 

 the classification expresses the real order of Nature, 

 and not simply the order which we may find con- 

 venient, there will be something more than mere 

 resemblance indicated in the various groups; or, 

 rather let me say, this resemblance itself is the con- 

 sequence of some community in the things com- 

 pared, and will therefore be the mark of some deep- 



