HEAD FORMATION IN APPLE TREES 161 



The drawings in Plates I-XVI are made from photographs. The figures in- 

 dicate the age of the tree at the time the photograph was made, and the letters 

 6 and a indicate before and after pruning, in each case where they are used. No 

 photographs were taken at four years because of the absence of the writer, 

 and at five years the trees were too close together to permit setting up a cam- 

 era. After one-half of the trees were cut out at six years of age photographs 

 were again made each year. There is little difference between the photographs 

 at six and seven years, and generally only the latter are shown. The camera 

 was set at nearly the same position relative to the tree each year, though with 

 increased size of tree it was necessary in later years to set farther away. 



In these drawings the development of the different branches may be followed, 

 from year to year, showing how they responded to the treatments given. 



