-68 



(6) The growth -temperature graphs are uniformly 

 flat at the top, which indicates that there is e consider- 

 able range of temperaturey all of which are about alike 

 in their suitability for producing the highest elongation 

 rates. Any temperature betvjeen 28° and 31°, inclxisive, 

 may be regarded as practically optimum, as far as the 

 results show. 'ITie graph for the la£:t 24 hours is more 

 pointed at the top than that for the whole culture period, 

 and the one for the whole period (about 110 ho\irs) is more 

 pointed than that for the first part of the period (about 

 86 hours). ^^/t-^ ^^^^^J f^^,A^ ^ fiMd/pt-^ e>/h^£y'^^ftu^ 



'e graphs are ell very 

 ^ the 



f^'^ ^(7) Tlie gro vrt,h- temper 8 tm<e 

 ^ the 



nearly s^mmietrical about A vertical line, representing 

 approximately 29.5°. as far as -aie results show. According 

 to the smoothed graphs, a maintained temperature of 25° 

 roey be expected to give sensibly the same grovvth rates 

 (\inder the conditions of these tests) as does one of 35°. 



(8) The ten-degree temperature coefficient 

 for the rate of shoot elongation for the entitle culture 

 period (about 110 hours from the beginning of the soaking 

 of the seedi) follows the general lew that has been worked 

 out by earlier studeatB in this field. Its value is 4.5 

 for the temperature interval fi?om 13° to 23°, about 2.5 for 

 the interval from 15° to 25° and 1.0 for the interval from 

 24° to 36°. The last point indicates that th'^ ojtiiniiia 

 teni)erature i's' to be considered as about ?.9'^Ci 



