Bul. 974, U. S. Dept. of Agriculture. PLATE XV. 
BLUEBERRY CUTTING SHOWING SECONDARY TWIG GROWTH. 
The cutting when first made was an unbranched twig. It was callused for a month, then 
chilled for two months, and then brought again into a temperature of about 60° F. From 
its stored food the cutting soon put out the short twig shown at the top of the illustration. 
When the four leaves on this twig had reached mature size and color and were manufac- 
turing new food in the form ofstarch, roots began to form onthecutting. Theroots brought 
in new mineral food, and then secondary twig growth took place in the form of the younger 
and stronger of the two twigs. (Natural size.) 
