Vol. XVIII IVIARCH 1, 1920 No. 11 



JOURNAJL OF 



AGRICULTURAL 

 RESEARCH 



CONXKNXS 



Page 



Effect of the Relative Length of Day and Night and Other 

 Factors of the Environment on Growth and Reproduc- 

 tion in Plants --_-_-.-_ 553 



W. W. GARNER and H. A. ALLARD 



(Contribution from Bureaa of Plant Industry) 



Mr 



PUBUSHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE. 



WITH THE COOPERATION OF THE ASSOCIATION OF 



LAND-GRANT COLLEGES 



Vw^ASMINOXON, D. C. 



WASHINQTON ; QOVERNMCNT ^RINTINO OFFICC ■ IOt» 



