200 



THE HORNED EARK. 



development in the region east of Hudson Bay; 0. a. hoyti in the region west; 

 while 0. a. praticola, normally centering in the northern prairie states border- 

 ing the Mississippi River, is rapidly extending its range to include the region 

 north of the Great Lakes (as well as pushing east to the Atlantic Coast). 

 It is evident, therefore, that the ai-ea south of Hudson Bay and north of Ohio 



Taken m Colorado 



HORNED LARK— FEMALE. 



Photo by B. R. Warren. 



affords a meeting ground for the three forms. It is the summer population 

 of this extensive debatable ground which invades Ohio in winter, and floods 

 us with intergrades. It is noteworthy in this connection that the Ohio breed- 

 ing birds, typical 0. a. praticola, so far as known, are largely lost to sight 

 during the winter inundation from the north ; and the question arises whether 

 they do not retire southward as a whole or in part during the winter season. 



