MIMICRY OF SPIDERS. 51 
rapidly influence the organism of the creature that a change of color is 
produced in harmony with its environment, I there raised this query : 
Can a spider have the power to influence at will the chromatophores or 
pigment bodies, so that she may change her color with the changing sites ? 
Mr. H. H. J. Bell has recently communicated an observation! which 
appears to be confirmatory of this suggestion. While traveling along the 
West Coast of Africa between two small towns on the Gold Coast 
(August, 1892), he was attracted by the appearance of what he 
supposed to be flowers upon the bushes bordering the path. On 
examining these he found that they were the webs of an orbweaving spider, 
whose spinningwork, according to the published description, resembles that 
of Argiope, as heretofore fully described by me. The spider’s body was a 
light blue color; and the legs, which were symmetrically disposed in the 
shape of an X across a whtte ribboned hub, were yellow, ringed with brown. 
The body of the spider resembled the corol of a flower, and the crossed 
legs gave it the semblance of petals. Mr. Bell speaks of the illusion as 
remarkable, and supposes this mimicry of an orchidlike flower serves not 
merely to protect the spider, but rather as an attraction to butterflies and 
other flower frequenting insects on which the aranead preys. 
The most interesting part of the observation, however, is the strange 
facility which the spider possessed of changing its color. Mr. Bell captured 
her in a white gauze collecting net, which was placed beneath 
her and into which she dropped when disturbed, as is the custom 
of many species. As soon as she touched the net the blue body 
color became white. On being shaken her body turned to a 
dark greenish brown. She was then placed in a glass tube, and gradually 
resumed her blue tint, but when shaken up always turned to a greenish 
brown. When placed in spirits the spider’s color became a gray brown, and 
so remained. The observation was repeated with like result, except that 
the second individual did not turn white, but passed immediately from 
her normal blue into a dark greenish brown. I have no comments to make 
upon this interesting and, as it seems to me, important observation, but 
give it place here, as of undoubted value in its bearing upon the interest- 
ing and perplexing problem of mimicry as it is presented in the life history 
of the various aranead species. I have never observed and do not remem- 
ber ever to have read of such instant and volitional changes of color. 
The slight changes which I have noted in spiders having metallic colors 
have been due to the play of light falling at and seen from different angles. 
The numerous and striking changes in the Shamrock spider (Epeira trifo- 
lium), so well illustrated in Plate I. of Vol. II., are produced gradually, 
and cannot be compared with the chameleonlike changes of the blue Orb- 
weaver observed by Mr. Bell. 
Flower 
Mimicry. 
Volition- 
al Color 
Changes. 
1 Nature, April 13th, 1893, page 558. 
