264 INSTINCTS OF BIRDS. 



among our native birds, though they have both 

 large famiUes to provide for, are, in their wild 

 state, polygamous. Indeed, it is evident from 

 the anatomical and physiological researches of 

 Mr. John Hunter and Dr. Jenner, that the 

 sexual connexions of birds, and the season at 

 which they breed, depend upon certain condi- 

 tions of their organization, and not upon any 

 information derived from experience or instruc- 

 tion. 



The propensity to propagate their species, in 

 this class of animals, is well known to be of 

 periodical occurrence; and dissection clearly 

 proves that it is always accompanied by a very 

 perceptible alteration in the reproductive system. 

 Besides, reclaimed birds, under the influence of 

 a plentiful supply of nourishing food, shelter 

 from the inclemency of the weather, and the 

 various stimuli with which domestication is 

 usually attended, may be kept in this state of 

 sexual excitation for several years, with com- 

 paratively, little interruption. A check to the 

 greatly increased activity of the reproductive 

 powers, so induced, is speedily given, however, 

 by a diminution of sustenance and exposure to 

 cold, at the same time also, a visible change 

 takes place in the physical condition of the 

 organs of reproduction. 



