I2 4 



BENNET M. ALLEN. 



until Aug. 3Oth. The former was killed when 24 mm. long. The 

 latter reached a length of 30 mm. It was extremely active and of 

 a bright silver color. It was unfortunately lost. 



TABLE SHOWING MORTALITY IN VARIOUS EXPERIMENTS. 

 In Soft Water. 



In City Water (Hard). 



We can see in these experiments the serious effect of the 

 Lawrence city water upon tadpoles deprived of the anterior lobe 

 of the hypophysis. An analysis of the water made June I shows 

 the following mineral content: 



In terms of mg. per liter. 



Total solids 584.0 



SiO 2 26.2 



Fe2Os A(2O: 2.6 fluctuates greatly from this 



figure to 13 mg. 



Ca 114.8 



Mg 16.0 



Naplus K 62.8 



Cl 78.0 at no time during experiment 



in free condition. 



SO 4 58.8 



HCO 3 388.0 



The Fe is the only ingredient that shows frequent fluctuation. 

 It is interesting to note in this connection the results of a test 

 control experiment. 



No. 27 X. On May I tadpoles from the same batch used in 

 27 were employed. These had been held in their development 

 at the operative stage by being kept upon ice. Soon after the 

 operation they were placed in city water. 



