2H 



The reduotion ant and climatic measurements to 



average 3 for the period and to relative values. 



As has been sta-^ed previously, each culture originally 

 comprising six plants was observed after about two -weeks of 

 grov;th from the seed and again after about four weeks from 

 the seed, and the coBsecutive cultures 7/ere started at inter- 

 vals of about 2 weeks. In many cases, however, the nximber 

 of plants from which records were actually taken was less 

 than six fit ^as never less t'-.an 3 and W:.s usually 4 or 5 

 in such cases) , on account of observab"'-e injury due to other 

 conditions than the ones here studied, such as insect attack, 

 etc. All plant data are^theref ore , stated as averages per 

 plant. Also, in many cases, the length of the preiod varies 

 slightly from 14 days for the two-week rjeriods and from S8 

 days for the four-week periods, and the averages per plant have 

 consequently been expressed as mean daily values for the res- 

 pective period. This method renders the plant measurements 

 for the different periods more strictly comparable. It should 

 be noted, however, that tfee growing periods "-ere 14 and .26 days 

 long in the malority of cases, and that variations in the X 

 length of the culture periods were slight. Considering the 

 2-week and 4-week plant values as measures of the results 



of plant processes acting through the periods, the mean daily 

 values represent mean daily increments or process rates, and 

 they will be termed "daily incremants", for their res-nective 

 periods, in the discussion that follov/s. Thus, for a. l,.j.i.u 



Iw 



10 cm. high at the end of a 13 day period, j^ cm. is re- 

 garded as the mean daily increment of increase in height, etc.. 



