200 THE HORNED LARK. 
development in the region east of Hudson Bay; O. a. hoyti in the region west ; 
while O. 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 area south of Hudson Bay and north of Ohio 
Taken in Colorado 
Photo by E. R. Warren. 
HORNED LARK—FEMALE. 
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 O. 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. 
