PLATE 27 



A. — Normal spring growth on a blueberry stem. This illustration is from a photo- 

 graph taken April 24, 1909. In the preceding season the plant had sent up an 

 unbranched shoot. After an outdoor chilling through the winter and early spring 

 it put out flowers and new twigs as shown in the illustration. The fact to be especially 

 noted is that the new growth on this stem took place from numerous buds. 



B. — Abnormal spring growth on a blueberry stem, due to lack of chilling. This 

 photograph was taken on May 19, 1913. Growth is taking place from only one bud, 

 the third from the tip. The uppermost bud is a flowering bud, the second a leaf 

 bud. Both are dead or dying. This plant had stood in the warm greenhouse all 

 winter and spring. If it had had the usual two to three months' chilling its starch 

 would have been transformed into sugar and the stem would have flowered and put 

 out new twig growth from numerous buds in the same manner as the stem shown in A. 

 187932°— 20 7 



