Smithsonian Report, 1919. — Coville. 
Plate 21. 
Blueberry Plant Forced Into Flower in September by Artificial 
Chilling. 
The plant that hero this cluster of flowers was brought indoors in late winter. It made new growth 
and during the cool weather of May it laid down flowering buds for the next year, as a blueberry 
plant ordinarily does in autumn. During the summer, however, the plant was given an arti- 
ficial winter by cliilling it for three months in an artificially refrigerated glass-covered frame 
exposed to daylight. When brought out of the frame, in September, the plant promptly 
flowered, as shown in the illustration. (Natural size.) 
