-to the fact that ell four graphs are relatively fl?t in 

 the region of the optimvim temperature range, end that the 

 solixtion graphs together indicate that the grovvth-temperatitre 

 graph tends to become less flat in this region as the seed- 

 lings become older.. The graph for the last 24 hours is ap- 

 parently more pointed above than that for the v;hole period, 

 and this, in turn, is less flattened than that for the first 

 part of the period. For the very first stages of germination, 

 it appears that the organism is not so sentltive to temperature 

 differences as it is for later stages. This is in general 

 agreement with many physiological observations. 



Another interesting point brought otit by these 

 graphs is that each curve is very nearly symmetrical about 



the vertical A3tie/ that represents its maximujn (optimum 



/ / 

 temperature), as far as these data show. This does not appear 



to be generally true in growth and other biological processes; 



in many cases reported in the literature (see Lebenbauer, cited 



just below, for example) the upward slope of this sort of graph 



is more gradual than the dov/nvmrd slope. 



L. 



