significantly different temperature relations if employed 

 with suitable concentration higher than the one \ised. V/ith 



A 



lower total concentrations than the one used, the temperature- 

 growth relations may be expected to show about the same temperature 

 optimtjra as the one shown by the three solixtion graphs of figure 

 I, since the distilled-water graph for the yfentire period/ agrees 

 v/ith the others in this respect. V/ith sufficiently different 

 total concentrations from those tested - either weaker or stronger 



- the details of graph curvature would probably be significantly 

 different from those for the solvition graphs shown in figure I. 

 With sufficiently higher total concentrations even the temperature 

 optlmura might be different from the one here indicated, and, - 

 as has been noted - the different sets of salts and salt propor- 

 tions tested in this study wotild then probably shov; marked dif- 

 ferences among themselves, so that they could not all be treated 

 as alike. 



Attention should be called to the fact that the recon- 

 mendation just stated may introduce a modification in the "Plan 

 for Cooperative Research". On page 15 of that publication, it is 



recommended that the temperature used for seed germination should 



^ o o 



be 25 - 26 . If the most rapid shoot elongation is desired, the 



higher temperature range here recommended should surely be u.sed, 

 when the other influential conditions are similar ito the ones here 

 tested. But it m.ay hot alv/ays be desirable, in preparing seedlings 

 for water cultures, to secure the most rapid development of shoots. 



Before leaving the consideration of the temperature 

 relations shovm by the graphs of figure 1, attention may be called 



