Aug. 2, 1920 Daily Development of Kernels of Hannchen Barley 395 



EXPERIMENTAL METHODS 



Such success as has been obtained in reducing the interval of sampling 

 is due in large part to the accuracy of tagging spikes at the same stage of 

 development. This, in turn, rests on an observation made several years 



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Fig. I. — Graph showing length, lateral diameter, and dorsoventral diameter of barley kernels for the as 

 days following flowering. The broken lines give the data for 1916, the soHd lines the data for 1917. 



before the work was started. In agronomic notes taken upon cereal 

 varieties, the time of heading and the time of ripening have always been 

 considered to be important statements of development. Of these, the 

 time of heading is thought to be especially valuable, because drouth and 

 other climatic factors that greatly influence maturity have usually 

 affected the plant but little up to this stage. 



