June, 1905] Packard: Color in a Flower Spider. 87 



the yellow center, on the white petals ; the fly alights on the flower, 

 probes the yellow flowerets head-down, when it is seized by the neck 

 and its blood is sucked ; this spider and two others on the fleabane 

 were all whitish, both cephalothorax and abdomen, the latter whiter 

 than the cephalothorax and legs. No yellow ones were seen this sea- 

 son, but it did not occur to me to look for them on the golden rod. 



I tried several experiments to see if these spiders would change 

 colors. I enclosed one small one in a test tube on the red corolla of 

 Rudbeckia for an hour, without any perceptible change, and again put 

 six in the tube for a day without any change. Four of the Misumena 

 were kept for four or five days in a bottle filled with wild rose leaves 

 but no change was observed. They were fed with house flies and 

 never appeared to see or notice the flies until the victim actually flew 

 or ran directly into the jaws of the spider. Also in neither season did 

 I find any reddish spiders on the wild rose. 



The remaining observations were made at Merepoint, in July, Au- 

 gust and September of 1904. On the 8th July of I found two on the 

 buttercup ; neither were yellow, but of the usual pale slightly green- 

 ish tint; a small one detected on the 12th was of a slight yellowish 

 green. July 12 two decidedly white ones occurred on the buttercup, 

 one with a red stripe on each side of the white abdomen. I placed 

 two of them in a bottle filled with buttercup flowers, and kept them 

 for three or four days without noticing any change of color. Four 

 examples were collected from the ox-eye daisy, but none were yellow, 

 one was whitish and the other greenish. One large one was yellowish 

 green. 



July 14 I put one in a box filled with heads of the ox-eye daisy, 

 it was faint yellowish, while one in a test-tube with the same kind of 

 flower is yellowish green. A rather large M. vatia was found with an 

 Andrena bee 12 mm. long in its jaws. 



I lined a glass bottle with tiger lily leaves and left a large white 

 one with red lateral stripes in it for three or four days, but no change 

 resulted. 



After this, with the flowering of the golden rod, the prevalent color 

 became yellow. The golden rods began to flower July 31, and on that 

 day five small whitish ones with no yellow tinge were found on the 

 freshly opened flowers. Four days after (August 4), when more Soli- 

 dago flowers had opened six small spiders were picked off, and one 

 half-grown spider all yellow, distinctly so, the cephalothorax and 



