256 ANIMAL INTELLIGENCE 



Later, the voice is used under such circumstances 

 very persistently. 



At first the young pigeon can scarcely sit up in any 

 fashion, but in a few hours this is possible, the greatest 

 difficulty being the management of the head and neck, 

 which often fall to one side o'r forward. 



The gradual progress in motor power and co-ordination 

 has been fully noted in the diaries. 



By-and-by the young pigeon recognises its own nest 

 when near it, and when alarmed will retreat to it. This 

 is a matter of vision largely, though, as noted in the 

 case of the young rabbits, there may be some sort of 

 memory of distance and direction through tactile and 

 muscular sensibility or otherwise. The subject is 

 obscure and worthy of more study. 



So close is the relation between psychic and physical 

 development, that, from the appearance of a bird, one 

 who has observed closely could be able to predict its 

 behaviour; and this seems to me to be undoubted 

 evidence of some sort of correlation between the physical 

 and the psychic. Now and then it will happen that 

 from one pigeon having been hatched a few hours in 

 advance of the other, by its being better able to persist- 

 ently thrust forward its beak for food to the parents, it 

 fairly starves the other one, or, if not completely, to 

 such an extent that the difference in both physical and 

 psychic development is very striking. Again, owing to 

 innate vigour, one of the two birds in the nest may 

 make a sudden advance, as was noted in the dog, in 

 which case the same result as just referred to follows. 



There are many signs of development that appear 

 progressively, such as changes in the shape of the skull 

 and beak, the method of holding the head, the relative 

 proportion of parts, etc. ; but, upon the whole, the rate 

 of feathering is a fairly good guide to progress, both 

 physical and psychic. 



