194 LIFE AND HABIT. 



rests, is that of pigs. These animals have run wild in 

 the West Indies, South America, and the Falkland 

 Islands, and have everywhere re-acquired the dark 

 colour, the thick bristles, and great tusks of the wild 

 boar; and the young have re-acquired longitudinal 

 stripes." And on page 22 of "Plants and Animals 

 under Domestication" (vol. ii. ed. 1875) we find that 

 " the re-appearance of coloured, longitudinal stripes on 

 young feral pigs cannot be attributed to the direct 

 action of external conditions. In this case, and in 

 many others, we can only say that any change in the 

 habits of life apparently favours a tendency, inherent or 

 latent, in the species to return to the primitive state." 

 On which one cannot but remark that though any 

 change may favour such tendency, yet the return to 

 original habits and surroundings appears to do so in 

 a way so marked as not to be readily referable to any 

 other cause than that of association and memory — the 

 creature, in fact, having got into its old groove, remem- 

 bers it, and takes to all its old ways. 



As regards the tendency to inherit changes (whether 

 embryonic, or during post-natal development as ordi- 

 narily observed in any species), or peculiarities of habit 

 or form which do not partake of the nature of disease, 

 it must be sufficient to refer the reader to Mr. Dar- 

 win's remarks upon this subject (" Plants and Animals 

 Under Domestication," vol. ii. pp. 51-57, ed. 1875). 

 The existence of the tendency is not likely to be de- 

 nied. The instances given by Mr. Darwin are strictly 

 to the point as regards all ordinary developmental and 

 metamorphic changes, and even as regards transmitted 



