4 BULLETIN 367, U.S. DEPARTMENT OF AGRICULTURE. 
ments. of the plant associations take place as the result of any partie- 
ular kind of treatment. It does not rest upon accurate surveys, but 
is the best approximation which could be compiled by continued ob- 
Tic. 2.—Outline map of the Santa Rita Range Reserve, Ariz., showing where quadrat 
collections haye been made and where hay has been cut. The small letters refer to 
collections made from 1903 to 1908. inclusive, the unaccented letters indicating spring 
and the accented letters fall collections. Likewise, the small figures refer to col- 
lections made from 1912 to 1914, inclusive, the figures without circles indicating collec- 
tions made in the spring and figures in circles fall collections. The shaded areas show 
where hay has been cut. The capital letters are introduced for convenience in reference. 
servations and study made while riding over the reserve in all di- 
rections twice a year for the past three years. It is not a strictly 
ecological map, though some of its areas approximate the plant zones 
of the region. There is no doubt that the natural distribution 
