THE PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 257 
Though differences between the mature forms of 
varieties of pigeons, so pronounced as regards physical 
form, less so psychically, but still real and always 
present, are obvious to even a superficial observer, it is 
interesting to note that even at an early date such 
differences do appear. To illustrate: the Dragoon is a 
bird of a very bold appearance, and as compared with 
many varieties, is somewhat wild. It has been spoken 
of as the “game bird” of the pigeon family. Such 
characteristics are manifest in the young before they 
are twenty days old. They peck sooner and more 
vigorously in the nest. They are shyer of approach, 
etc. 
This cannot be explained by a more rapid develop- 
ment, for several other varieties mature sooner than 
they do. 
Changes in the colour of the iris are as significant, 
it would seem, as in mammals, 
Some Conclusions. 
Pigeons, when hatched, and for the first day or two, 
keep their eyes mostly closed, though the eyelids are 
not actually united at birth. 
They are both blind and deaf when they first emerge 
from the shell, and for a certain period afterwards. 
Perfection of hearing and vision are gradually but 
rapidly acquired. 
Taste and smell cannot be demonstrated at birth, but 
can be shown to exist some days later. 
From the first tactile sensibility and capability for 
painiul sensations exist in exquisite development. 
Pigeons, even more than mammals, seem to be 
sensitive to heat and cold. 
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