,6oo Journal of Agricultural Research voi. xviii, no. n 



simulates the normal behavior of these plants out of doors under the 

 influence of the long summer days. 



Through the kindness of Dr. D. N. Shoemaker, several varieties of 

 Lima beans (Phaseolus lunatus L.), F. S. P. I. No. 46153, from Chincha, 

 Peru, and F. S. P. I. No. 46339, from Guayaquil, Eucador, were trans- 

 planted from the field to the greenhouse. Several plants of each of 

 these varieties were transplanted into each house on October 18, 1919. 

 Up to that time the plants had not flowered but gave evidence in the 

 field of being extremely late varieties in this latitude. The control plants 

 grew rather slowly but soon became markedly floriferous, setting pods 

 freely. On the other hand, the plants in the artificially illuminated house 

 produced an exceptionally rank growth of vines but did not flower. 



Biloxi, Tokyo, Peking, and Mandarin varieties of soybeans were sowed 

 November 1,1919, and came up November 10 in both houses. In the con- 

 trol house the first blossoms appeared on the Biloxi and Mandarin about 

 December 24, and on the Tokyo and Peking about December 18. In the 

 artificially lighted house the early variety, Mandarin, blossomed on about 

 the same date as in the control house; but under the longer light exposure 

 the plants continued to grow vigorously, and only a very few blossoms 

 appeared, suggesting a tendency toward gigantism. The few blossoms 

 which formed, however, were normal and developed normal pods, while 

 those on the control plants were cleistogamous and sterile. As late as 

 February 12 the other three varieties showed no indications of blossoming. 

 On that date all varieties were much taller in the electrically lighted house 

 than in the control house. 



Seed of Beggar-ticks {Bidens frondosa L,.) were sowed in both houses on 

 November 19, 1919, and came up in each on December i. When the 

 plants were very small they were transferred from the flats to 5-inch 

 pots. The transplanting took place on December 19, and on January 12 

 all the control plants in the unlighted house, 8 or 10 in number, were 

 showing tiny flower heads, although these had attained a height of only 

 I to 2 inches. These flower heads came into expression as soon as the 

 plants had developed the second pair of foliage leaves above the cotyle- 

 dons. The plants in the lighted house continued to produce vegetative 

 growth and gave no evidence of producing flower heads as late as February 

 12. Two of these plants which had attained a height of 8 to 9 inches in 

 response to the lengthened period of illumination in the artificially lighted 

 house were transferred to the control house on December 19. On Jan- 

 uary 12 both plants had produced flower heads in response to the natu- 

 rally short winter days prevailing in this house and gave promise of 

 blossoming in a short time. The sister plants remaining in the illuminated 

 house continued to produce vegetative growth, with no evidence of blos- 

 soming. 



Buckwheat {Fagopyrum vulgare Hill) was sowed November i, 191 9, 

 and came up in both houses on November 7. In the control house 28 



