230 EVIDENCE THAT DAPHNIA9 



covered part and replaced them with an equal number 

 of fresh ones. If, then, some Daphnias preferred red or 

 blue, I ought thus to eliminate the others, and gradually 

 to get together fifty agreeing in this taste. This, how- 

 ever, was not the case. In the first experiment, an hour 

 after the Daphnias were placed in the vessels there 

 v/ere, out of 60, 41 under the yellow, 16 under the red, 

 and 15 under the blue, the remaining 9, 34, and 35 

 respectively being in the uncovered portions. These, 

 then, I removed and replaced by others. After doing 

 this five times, and thus adding 80 in the yellow division, 

 187 in the red, and 209 in the blue, the numbers were 37 

 under the yellow, 15 under the red, and 6 under the blue. 



In the second experiment, the numbers after the 

 first hour were 32 under the yellow, 10 under the red, 

 and 11 under the blue. After five observations, during 

 which 86 were added to the yellow division, 188 to the 

 red, and 180 to the blue, the numbers were — under the 

 yellow, 35 ; red, 11 ; blue, 15. 



In the third experiment, the numbers after half an 

 hour were 40 under the yellow, 14 under the red, and 8 

 under the blue. After five observations, during which 

 73 were added to the yellow, 186 to the red, and 20G 

 to the blue, there were — under the yellow, 43 ; nnder 

 the red, 15 ; and under the blue, 7. 



In the fourth experiment, the numbers after half an 

 hour were 38 under the yellow, 15 under the red, and 

 14 under the blue. After six observations, during 

 which 89 were added to the yellow, 166 to the red, and 

 176 to the blue, the numbers were — under the yellow, 

 30 ; under the red, 19 ; and under the blue, 10. 



In the fifth experiment, the numbers after half an 

 hour were 40 under the yellow, 14 under the red, and 



