PHOTOPERIODISM 517 



Van Overbeek, J. (1945) Flower formation in the pineapple plant as controlled by 

 2,4-D and naphthaleneacetic acid. Science, 102: 621. 



(1946) Control of flower formation and fruit size in the pineapple. Botan. 



Gaz., 108: 64-73. 



Van Overbeek, J., and H. J. Cruzado (1948a) Flower formation in the pineapple 

 plant by geotropic stimulation. Am. J. Botany, 35: 410-412. 



(1948b) Note on flower formation in the pineapple induced by low night 



temperatures. Plant Physiol., 23: 282-285. 



Van Overbeek, J., E. S. de Vazquez, and S. A. Gordon (1947) Free and bound auxin 



in the vegetative pineapple plant. Am. J. Botany, 34: 266-270. 

 Wassink, E. C., C. M. J. Sluijsmans, and J. A. J. Stolwijk (1950) On some photo- 

 periodic and formative effects of coloured light in Brassica rapa, F. oleifera, subf . 



annua. Koninkl. Ned. Akad. Wetenschap. Proc, 53: 1466-1475. 

 Went, F. W. (1941) Effects of light on stem and leaf growth. Am. J. Botany, 



28: 83-95. 

 Whitaker, W. L. (1938) The question of a seasonal sterility among the Eskimos. 



Science, 88: 214-215. 

 Withrow, A. P., and R. B. Withrow (1943) Translocation of the floral stimulus in 



Xanthiurn. Botan. Gaz., 104: 409-416. 

 Withrow, A. P., R. B. Withrow, and J. P. Biebel (1943) Inhibiting influence of the 



leaves on the photoperiodic response of Nobel spinach. Plant Physiol., 18: 



294-298. 

 Withrow, R. B., and H. M. Benedict (1936) Photoperiodic responses of certain 



greenhouse annuals as influenced by intensity and wave length of artificial light 



used to lengthen the daylight period. Plant Physiol., 11: 225-249. 

 Withrow, R. B., and J. P. Biebel (1936) Photoperiodic response of certain long- and 



short-day plants to filtered radiation applied as a supplement to daylight. Plant 



Physiol., 11: 807-819. 

 Withrow, R. B., and A. P. Withrow (1940) The effect of various wave bands of 



supplementary radiation on the photoperiodic response of certain plants. Plant 



Physiol., 15: 609-624. 



(1944) Effect of intermittent irradiation on photoperiodic responses. Plant 



Physiol., 19: 6-18. 



Yeates, N. T. M. (1949) The breeding season of the sheep with particular reference 

 to its modification by artificial means using light. J. Agr. Sci., 39: 1-42. 



Manuscript received by the editor May 20, 1953 



