Chap. XIV.] ANALOGICAL RESEMBLANCES. 219 



(Antechinus) of Australia. These latter resemblances 

 may be accounted for, as it seems to me, by adaptation 

 for similarly active movements through thickets and 

 herbage, together with concealment from enemies. 



Amongst insects there are innumerable similar in- 

 stances; thus Linnaeus, misled by external appearances, 

 actually classed an homopterous insect as a moth. We 

 see something of the same kind even with our domestic 

 varieties, as in the strikingly similai* shape of the body 

 in the improved breeds of the Chinese and common pig, 

 which are descended from distinct species; and in the 

 similarly thickened stems of the common and specifically 

 distinct Swedish turnip. The resemblance between the 

 greyhound and the racehorse is hardly more fanciful 

 than the analogies which have been drawn by some 

 authors between widely different animals. 



On the view of characters being of real importance 

 for classification, only in so far as they reveal descent, 

 we can clearly understand why analogical or adaptive 

 characters, although of the utmost importance to the 

 welfare of the being, are almost valueless to the system- 

 atist. For animals, belonging to two most distinct lines 

 of descent, may have become adapted to similar condi- 

 tions, and thus have assumed a close external resem- 

 blance; but such resemblances will not reveal — will 

 rather tend to conceal their blood-relationship. We 

 can thus also understand the apparent paradox, that 

 the very same characters are analogical when one group 

 is compared with another, but give true affinities when 

 the members of the same group are compared together: 

 thus the shape of the body and fin-like limbs are only 

 analogical when whales are compared with fishes, 

 being adaptations in both classes for swimming through 



