15- 



Me&s\ireme nts and Results. 



Intro ductio n. As has been stated, each 

 culture solution was removed and replaced by a fresh 

 one on the second, third, and foiirth day of tiie culture 



QD 



period, the cixltui^es being discontinued/' the fifth day. 



the 

 These renewals of/solutions did not occur, hov/ever, at 



exactly 24 ho\ir intervals and the total length of the 



culture period was always less then 5 days. The variation 



from the time schedule- was not great in any esse and all 



cultures of any series (21 solutions of a single solution 



type, vjith eech of the seven temperatures tased) were 



subjected to the same time periods between renewals^and to 



the same total period. On the third day of the period, 



all seedlings v/lth shoots 1 cm. or more in length were 



shoot 

 counted and recorded. On the fourth day, eacb/l cm. long 



or longer was measured, and record v/as made showing the 

 number of seedlings in each culture that were 1, 2, 5, etc.. 

 cm. high. All shoots were again measured on the fifth day, 

 when the cultures were discontinued. To avoid much disturb- 

 ance, measiirements made prior to the final one v/ere only 

 approximately correct, about to a precision of 1 era., but the 



fifth-day measurements were carefully made, to a precision of 



bei ng 

 1 mm., each seedling I removed from the solution for 



measurement. These two measurements mny be termed 



