THE 0KIGIN OF THE VARIETIES OF PIGEONS. 87 



nary faculty of turning head over heels in the air, instead of pursuing a distinct 

 course. And, lastly, the dispositions and voices of the birds may vary. Thus the 

 case of the pigeons shows you that there is hardly a single particular, — whether of 

 instinct, or habit, or bony structure, or of plumage, — of either the internal economy 

 or the external shape, in which some variation or change may not take place, which, 

 by selective breeding, may become perpetuated, and form the foundation of, and 

 give rise to, a new race." 



