Are Acquired Habits inherited? 297 



and, as Mr. Warde Fowler suggests, of wagtails, and a 

 great number of peculiarities in behaviour, and perhaps 

 differentiae in the mode of flight among birds that flock 

 together. It will be seen how many instinctive activities 

 may not unreasonably be claimed by the non-trans- 

 missionist as directly due to natural selection. 



Among instincts, there are few examples of the second 

 class which includes those due to definite correlation. 

 Perhaps we might place among them the development of 

 the cuckoo instinct, as definitely correlated with variations 

 in laying, possibly due to the effects of polyandry. 



A small percentage of activities remains — or rather 

 perhaps they should be termed instinctive traits — which 

 are performed with congenital definiteness, but which do 

 not appear to fall very readily under either of these heads. 

 They must, therefore, either find their explanation in the 

 transmission of acquu'ed habit, or must be regarded as 

 incidental characters associated with the essential activities 

 of the organism in what has been termed the congenital 

 nexus. It may indeed be contended that the moorhen's 

 water-bath, or the chick's sand-bath, and the preening 

 of the feathers and down by young birds are of utilitarian 

 import, since they keep the organism in health, and serve 

 to remove parasites; though whether they can fairly be 

 regarded as of selection-value, deciding between survival 

 or elimination, is open to question. Let us for the 

 moment grant this much to the natural-selectionist. 

 There remains the fact that these operations are per- 

 formed with delicate but quite recognizable shades of 

 distinction by the young birds, in each of which the dis- 

 tinctive traits are congenitally true to those of their 

 kind. Chicks, ducklings, moorhens, all perform their 

 toilet in their own way. To one who carefully watches 

 from day to day the habits of young birds, there are 



