94 A. S. PEARSE 



placed in each of the six dishes (black, red, yellow, green, blue 

 and white respectively) ; on August 2 3 two more white spiders 

 were added to each dish. Daily notes were then made as to the 

 condition of the eighteen spiders under observation until Septem- 

 ber 6, a period of fourteen days (during which time eight indi- 

 viduals died). Although four individuals changed a little and 

 looked as though they might be about to take on a slightly 

 different tint, none of the animals assumed a color that could 

 be called anything but white. 



Experiment 2. September 3, 1909, five white spiders were 

 placed on a bunch of goldenrod flow^ers {Solidago sp. ?), yellow, 

 and five yellow spiders on a bunch of milfoil {Achillea Millefolium) , 

 white. The flowers were in bottles which rested in large pans 

 of water so that the spiders could not escape. Both dishes were 

 placed before a window so that they were illuminated by the 

 morning sun. The spiders were observed daily until all had been 

 drowned. On the milfoil three were drowned after one day, 

 one after four days, and the last after fifteen days ; on the yellow^ 

 flow^ers, three lived four days, one eight, and one thirteen. None 

 of these spiders showed any color changes. 



Experiment 3. For this experiment two of the color boxes 

 described on page 81 were used (Fig. i). On August 31, 1909, 

 seven yellow spiders were placed in a white box and a like number 

 of the same color in a yellow box. All but one of these remained 

 alive for more than seventeen days ; none of them changed color. 



On September 6, 1909, six white Misumenas were placed in 

 a w^hite box, and a corresponding number of the same color in a 

 yellow box. These were all alive on September 17 (10 days); 

 on September 24, onh^ one was alive in the white box and three 

 in the yellow; on October 7, there was no further mortality in 

 the white box but all those in the yellow had died. None of 

 these spiders changed color. 



Experiment 4. IVIethods like Experiment i. Up to November 

 27 the glass jars containing the spiders rested on a shelf in a 

 laboratory room ; after that they were on a table before a window. 



September 19, 1910, six yellow^ males and two yellow females 

 were put in two "white jars." Two of the males turned white 

 between October 8 and 21, all the others died before that time 

 except one male (who remained yellowish until he escaped on 

 November 10). On November 24, the two surviving (then white) 



