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 

 painful sensations exist in exquisite development. 



Pigeons, even more than mammals, seem to be 

 sensitive to heat and cold. 



ft 



