The Three Barriers. 175 



is to affirm too much, Mr. Darwin may still ask 

 (as above) " What special difficulty there is in 

 believing" it? Especially "since it certainly is 

 not true that new organs appear suddenly in 

 any class." 1 



The counterpart of this strange story is still 

 more worthy of a place in the record of the 

 "Thousand and One Nights." For not only 

 have so many terrestrial creatures been derived 

 from an " aquatic origin " 2 by that marvellous 

 metaphor called Natural Selection, but, on the 

 other hand, there are not wanting some land- 

 animals that, renouncing their original nature, 

 have become aquatic. Surprising as it may be 

 to learn that a giraffe was once a fish, it is not 

 less surprising to be told that a whale was once 

 a bear, And yet, " In North America, the black 

 bear was seen by Hearne swimming for hours 

 with widely-open mouth, thus catching, like a 

 whale, insects in the water. / see no difficulty 

 in a race of bears being rendered by Natural 

 Selection more and more aquatic in their struc- 

 ture and habits, with larger and larger mouths, 

 till a creature was produced as monstrous as a 

 whale." 3 With this difference, however : that, 



1 " Origin of Species," First Edition, p. 214. 



2 Ibid., p. 215. 



In the third and subsequent editions, the latter part 



