368 



REACTIONS OF DAPHNIA PULEX TO LIGHT AND HEAT. 



TABLE I. 



TIME (IN SECONDS) REQUIRED BY DAPHNIA NUMBER 1 TO SWIM 50 CM., WHEN INFLUENCED BY LIGHT ALONE AND 



WHEN INFLUENCED BY LIGHT ACCOMPANIED BY HEAT. 

 7 P.M., Dec. 11, 1901. Temperature of Water 20 C. 



TABLE II. 



THE AVERAGES FOR FIVE SERIES OF EXPERIMENTS LIKE THAT OF TABLE I. EACH COLUMN CONTAINS THE AVERAGES 

 FOR TEN TRIPS MADE BY EACH OF FIVE DAPHNIA (NUMBERS 1 TO 5). 



