HEREDITY 487 



echo of the distant past when the dog before it settles itself 

 to sleep turns round and round in the imaginary herbage 

 of the hearthrug. The hand of the past is upon it in the 

 passivity of sleepiness, and it does needlessly what its ances- 

 tors did to a purpose. So in the donkey " we see signs of 

 its original desert life in its strong dislike to cross the 

 smallest stream of water ". We are told that some Scottish 

 cows transported to unwonted conditions on an American 

 ranch hid their calves in the thicket, and went to feed in 

 the open in the old approved fashion of wild cattle. The 

 novel circumstances were really primitive and they awakened 

 a long dormant instinct. Many examples of this sort havo 

 been collected by Robinson in his Wild Traits in Tame Ani- 

 mals, and while there is need for criticism, there can be no 

 doubt as to the persistence with which the past lives on in 

 the present. Many outcrops that seem quite perplexing in 

 man are probably anachronistic stirrings of ancestral habits, 

 (c) Another set of illustrations of the past living on in 

 the present is afforded by the facts that are now familiar 

 in regard to the staying power of certain unit-characters or 

 Mendelian characters that are relatively superficial in nature, 

 and cannot be regarded as forming part of the main frame- 

 work of the inheritance. When we consider how the Ilaps- 

 burg lip has persisted for four centuries in Austria and 

 Spain, how night-blindness has continued to crop out for ten 

 generations and in hundreds of individuals in one family 

 history beginning with 1637, or how brachydactylism (hav- 

 ing the fingers all thumbs) may last for six generations, 

 we realise that the hand of the past is living indeed, and 

 inexorable. We have already mentioned the laciniate variety 

 of the Greater Celandine (Chelidonium ma jus), which sud- 

 denly appeared about 1590 and has been breeding true ever 



