-42- 



The rates for the distilled water cnltures 

 show the same general temperatiire relations as those 

 shown tj fj) the highest rates, (2) the lowest rates 



and (3) the grand averages, for the nutrient solution 



o o 

 cultures. in all cases the rates for 28 and 31 are 



the highest and about alike, those for 25 and 35° are 



lower and about alike, those -^or 21°, 17° and 13° ^^^ 



progresively stilllower. 



The distilled-water value is markedly lov;er, 



however, fin every case excepting that for 13 ), than 



is the corresponding highest rate or the corresponding 



grand average value from the nutrient solution cultures. 



Furthermore, the distilled-water value is somewhat lower 



than even the lowest rat§ from the nutrient solution 



cultures in all cases, excepting that for 13°. It appears 



from table ^^ that the cultures with distilled water generally 



gave mean ratesfebout half as great as th^ corresponding rates 



obtained with nutrlnnt solutions, -js- tlie lov-est temperature 



tested (13), the distilled-water cultures gave a rate just 



equal to the grand average for this temperature with nutrient 



solutions. All of the solutions tested were of about the 



same osmotic value (eoiuivalent to about 0.1 atm. of osmotic 



pressure), so that the one feature by v;hich all soluions 



agreed among themselves and yet differed from distilled 



water is with regard to osmotic value. The solutions differed 



