[MILLS | PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 247 
The records show that they can soon see, and so early as the sixth day 
can distinguish objects at the distance of one foot, 
The diaries give facts which will enable one to note the rate at which 
progress in this direction takes place. By about the tenth day the 
pigeon’s vision for objects anywhere in a good sized loft is excellent. 
The practical absence of the winking reflex in young pigeons is 
noteworthy. However, it is not easy to cause mature birds to wink. 
Moving an object before its head when the bird is held in the hand causes 
movement of the head rather than winking. 
The pupillary reflex is, however, soon and well established in birds. 
There is no doubt that the newly hatched pigeon is deaf; but I have 
found that hearing may be demonstrated on the second day in some 
cases. 
It is very rare,indeed, that pigeons manifest any signs of hostility, 
etc., when caught up in the hands. 
Birds sitting on the nest will sometimes, however, peck vigorously, 
and the early age at which this pecking or snapping of the beak is 
exhibited, seems to me noteworthy. It illustrates how purely instinctive 
the matter is. It reminds me forcibly of the hissing of the young kitten, 
the more so as both are often evidences of surprise rather than real 
hostility. 
I have not noticed that the newly-born pigeon has voice, but after a 
few days (five in one case) the bird “squeaks” on the approach of the 
parents and especially when being fed. 
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 or forward. 
The gradual progress in motor power and co-ordination has been 
fully noted in the diaries. 
By-and-by the young pigeon recognizes 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 
