496 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



Expt., Jan. 16, 1903. 

 Stentors are pale. 



Media. hr. 1 da. 7 da. 



.00100 m. CaCl 2 .... 

 .00100 m. K 2 HP0 4 . . . 

 .00050 m. CaCl 2 



and L ... 50 48 34 



.00050 m. K 2 HP0 4 , 



Using calcic chloride as a standard, we should say that the Stentors 

 here used present a low metabolic pitch. In view of this the higher 

 meau result, and especially the longevity shown by the combination, 

 strongly indicate that Stentor is better adjusted to a combination of phy- 

 siological salts than td any single salt of that combination, provided that 

 the constitutive proportions of the salts be observed. This is an im- 

 portant proposition for my subsequent discussion. 



50 



50 



33 



35 



50 



60 



January 22. 



.00100 m. CaCl 2 



.00075 m. CaCl 2 \ 



and \ .... 



.00025 m. MgS0 4 J 

 .00050 m. CaCl 2 



and 

 .00025 m. K 2 HP0 4 



and 

 .00025 m. MgS0 4 J 



The animals at the end of this last experiment were healthier in color 

 than at the end of the following experiment : 



.00075 m. CaCl 2 \ 



and I 50 54 



.00025 m. K 2 HP0j 



I have ventured to record together the experiments of January 17 and 

 22 on the basis of their nearly equal results with calcic chloride. 



