496 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



) 



ExpL, Jan. 16, 1903. 

 Stentors are pale. 



Media. hr. 1 da. 7 da. 



.00100 m. CaCla .... 

 .00100 m. KoHPOi . . . 

 .00050 m. CaCla \ 



and I ... 50 48 34 



.00050 m. K2HPO4 J 



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 

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

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

 siological salts than to 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. 



Expts., Jan. 17 and 22, 1903. 



January 17. 

 Media. 



.00100 m. CaCl, .... 



Ohr. 

 50 



1-2 da. 



29 



.00080 m. CaClo 



and 

 .00020 m. MgSO^ 



1 



50 



32 



January 22. 



.00100 m. CaCls 50 33 



.00075 m. CaCla 



and !► 50 35 



.00025 ra. MgS04 

 .00050 m. CaClg 



and 

 .00025 m. K2HPO4 1 50 60 



and 

 .00025 m. MgSOi . 



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

 than at the end of the following exjieriment : 



.00075 m. CaCL \ . 



and i 50 54 



.00025 m. K.JIPOJ 



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

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



