SELECTED BIBLIOGRAPHY 583 



Went (1938), on the basis of recent experiments, has postulated the exist- 

 ence of another group of hormones in plants for which he proposes the name 

 calines. He considers that there are at least three such hormones: (i ) Rhizo- 

 caline, produced in aerial organs, is necessary for root formation. (2) Cau- 

 localine is formed in the roots but is necessary for elongation of stems or 

 lateral buds. (3) Phyllocaline, apparently formed in the leaves, is necessary 

 for leaf growth. Rhizocaline and caulocaline are believed to be effective only 

 in the presence of auxins. This is a highly speculative, but nevertheless 

 provocative hypothesis. 



Similarly it has recently been postulated that flowering occurs only in the 

 presence of a specific hormone which has been called florigen (Chap. 

 XXXIII). 



Suggested for Collateral Reading 



Boj'sen Jensen, P. Groivth hormones in plants. Translated and revised by 

 G. S. Avery, Jr., and P. R. Burkholder. IVIcGraw-Hill Book Co. New 

 York. 1936. 



Went, F. W., and K. V. Thimann. Phytohormones. Macmillan Co. New 

 York. 1937. 



Selected Bibliography 



Avery, G. S., Jr., and P. R. Burkholder. Polarized growth and cell studies 

 on the Avena coleoptile, phytohormone test object. Bull. Torr. Bot. 

 Club 63: 1-15. 1936. 



Averj^ G. S., Jr., P. R. Burkholder, and H. B. Creighton. Avena coleoptile 

 curvature in relation to different concentrations of certain synthetic sub- 

 stances. Amer. Jour. Bot. 24: 226-232. 1937. 



Bonner, J., and J. English, Jr. A chemical and physiological study of trau- 

 matin, a plant icound hormone. Plant Physiol. 13:331-348. 1938. 



Boysen Jensen, P. Growth regulators in the higher plants. Ann. Rev. 

 Biochem. 7: 513-528. 1938. 



Cholodny, N. Beitrdge zur Analyse der geotropischen Reaktion. Jahrb. 



Wiss. Bot. 65 : 447-459- 1926. 

 Clark, W. C. Polar transport of auxin and electrical polarity in coleoptile of 



Avena. Plant Physiol. 12 : 737-754- 1937- 

 Haberlandt, G. Wundhormone als Erreger von Zellteilungen. Beitr. Allg. 



Bot. 2: 1-53. 1921. 



Hitchcock, A. E., and P. W. Zimmerman. Absorption and movement of syn- 

 thetic growth substances from soil as indicated by the responses of aerial 

 parts. Contr. Boyce Thompson Inst. 7: 447-476. 1935- 



Hitchcock, A. E., and P. W. Zimmerman. Effect of growth substances 

 the rooting response of cuttings. Contr. Boyce Thompson Inst. 8 : 63 

 79. 1936. 



n 



