342 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



of which encircled the web like a charming frame to a picture. ^ Again, 

 one niaj^ sec tlic round webs of Epcira spun among lilies,'* and hung 

 within full blossoming sprays of honeysuckle. Indeed, at every point in 

 Nature where flowers appear, there also appear spiders erecting their domi- 

 ciles, weaving their snares, and spinning their cocoons. 



In like manner many of the wandering tribes spend their lives in 

 arboreal situations, continually stalking their prey, and plying the varied 

 industries characteristic of their species among grasses, shrubs, blossom- 

 ing trees, vines, and beds of flowers. Are they utterly unconscious of the 

 color effects among which they continually move? Or if, on the other 

 hand, they have some sense of color, in what degree is it possessed? 

 These are interesting questions, and to some extent they have been solved, 

 although much remains to be proved. 



It cannot, of course, be known that the light waves of various lengths, 

 whose vibrations result in color, jDroduce upon the spider's organ of vision 

 effects similar to those known to man and many of the liigher mannnals. 

 But that some effect is produced seems clear, and that this is analogous 

 to the color sense in man, we may perhaps safely assume ; for we can 

 only think and speak of the sensations of spiders in terms of our own 

 conscious states. 



The late Prof. Paul Bert claimed that all animals see the rays of the 



spectrum as we do ; that beyond this they see nothing that is unseen by 



us, and that, in the extent of the visible region, the differences 



n rus- |3g^y^,gg]^ ^}^g illuminating powers of the different color rays are 

 taceans. or j 



the same for them as for us.^ He rests these conclusions on 



experiments made on a small fresh water crustacean belonging to the 

 genus Daphnia. Sir John Lubbock dissents from this generalization as 

 too sweeping and based upon an insufficient foundation,* but, as the 

 result of numerous experiments with Daphnia pulex, concludes that while 

 it would be impossible to prove that these crustaceans actually perceive 

 colors, to suggest that the rays of various wave lengths produce on their 

 eyes a different impression other than that of color, is to propose an en- 

 tirely novel hypothesis. At any rate, he thinks that he has shown that 

 they do distinguish between waves of different lengths, and prefer those 

 which to our eyes appear green and yellow.'' 



On the other hand, M. Merejkowski denies to the crustaceans any 

 sense of color whatever. He thinks that they distinguish very well the 

 intensity of the ethereal vibrations, their amplitude, but not their number. 

 In the mode of tlieir perception of light there is a great difference 



> Vol. I., page ,344, Fig. 335. « Ibid., Fig. 104. 



^ "Arciiive fie Pliisiologie," 1869, page 547. * "Ants, Wasps, and Bees," page 220. 



'^ Sir Joiin Lubbock : " On tlie Sense of Color among some of tlie Lower Animals," 

 Linnreau Society's .Journal Zoology, Vol. XVII. (1883), page 214. See also "Senses and In- 

 stincts," page 228. 



