GREY BREASTED MARTINS 



341 



they are his proper food, because he has so been fed from 

 the time of hatching, and he finally learns how to catch them 

 only after instruction by and imitation of his parents. 



These observations show, in this bird at any rate, 

 though probably in many others that certain habits have 

 been acquired, due to the protection afforded by the advance 

 of civilization which, if the bird were transplanted from civ- 

 ilization to ancient conditions, would be of great detriment 

 to it. These newly acquired habits dominate its natural 

 instincts. 



