342 



THE STUDY OF ANIMAL LIFE CHAP. 



By rudimentary organs also the same conclusion is 

 suggested. What mean the unused gill-clefts of reptiles, 

 birds, and mammals, unless the ancestors of these classes 

 were fish-like ; what mean the two sets of functionless 

 teeth in unborn whale-bone whales, unless they are 

 vestiges of useful teeth which their ancestors possessed ? 



Similar vestiges are common 

 among the higher animals. In 

 man alone there are about 

 seventy little things which 

 might be termed rudimentary ; 

 our body is a museum of relics. 

 Historical. Every one recog- 

 nises that animals have not 

 always been as they now are ; 

 we have only to dig to be con- 

 vinced that the fauna of the 

 earth has had a history. But 

 it does not follow that the suc- 

 cession cf fauna after fauna, 

 age after age, has been a pro- 

 gressive evolution. What evi- 

 dence is there of this ? 



In the first place, there is 

 the general fact that fishes 

 appear before amphibians, and 

 these before reptiles, and these 

 before birds, and that the same 

 correspondence between order 

 of appearance and structural 

 rank is often true in detail 

 within the separate classes of 

 animals. There are some mar- 

 vellously complete series of 

 fossils, especially, perhaps, that 

 of the extinct cuttlefishes, in 

 which the steps of progressive 



evolution arc still traceable. Moreover, the long pedi- 

 gree of some animals, such as the elephant or the horse, 

 has been worked out so perfectly that more convincing 



FIG. 113. FORK AND HIND 

 FEET OF THF. HORSE AND 

 SOME OF ITS ANCESTORS, 

 SHOWING GRADUAL RE- 

 DUCTION OF DIGITS. 



(From Chambers's Encyclop. ; 

 after .Mavsli.) 



