June, 1897] Webster: On Protective Mimicry. 13 



complete, and I have no doubt but that it not only escaped its enemies, 

 but secured a better supply of food in consequence of its concealment, 

 though in plain light, in a most exposed position. Mr. Henry O. Forbes, 

 in his "A Naturalist's Wanderings in the Eastern Archipelago," p. 63, 

 gives a similar experience of his in Java. In this case the observer saw 

 what he supposed to be a butterfly at rest on a splotch of bird excreta on 

 a leaf. Mr. Forbes carefully approached his prize until he was able to 

 seize it between his fingers, when, to his astonishment, the wings parted 

 from the body, which was left behind, and he still thought it had ad- 

 hered to a small splotch of bird excreta until he touched the latter with 

 his finger to find if it was glutinous, when, to his delighted astonishment, 

 he found that the supposed excreta was really a peculiarly colored spider 

 lying on its back, with its feet crossed, and on an irregularly shaped 

 film of web, appearing like a splotch of excreta, with its central and 

 denser portion of a pure chalk like color, streaked here and there with 

 black, the white margin being drawn out into a narrow streak, with a 

 slight thickening at termination near the margin of the leaf. Two years 

 after, in Sumatra, Mr. Forbes, while waiting for his servants to procure 

 some botanical specimens for him, rather dreamily plucked what ap- 

 peared to be an excreta-marked leaf, and, while looking at it, mentally 

 wondered why it was that he had never found a second specimen of the 

 curious spider found in Java, when suddenly the supposed excreta bit 

 him, and he was astounded to learn that he actually had a second spec- 

 imen in his hand (loc. cit., p. 216). 



In transmitting his specimens to Rev. O. P. Cambridge, for deter- 

 mination, Mr. Forbes used this expression : "the similitude is so exact 

 that the spider might have had consciousness, and it could not have 

 been more exact if the spider did have it," referring, of course, to the 

 placing of itself on its sheet of web and the deceptive resemblance pre- 

 viously mentioned, though he really had no intention of crediting the 

 spider with any conscious design, as Rev. O. P. Cambridge at first supposed. 

 The latter gentleman, however, offered the following explanation of the 

 phenomenon (loc. cit., pp. 11 9-1 21) : "It seems to me, on the con- 

 trary, that the whole is easily explained by the operation of natural se- 

 lection, without supposing consciousness in the spider in any part of the 

 process. The web on the surface of the leaf is evidently, so far as the 

 spider has any design or consciousness in the matter, spun simply to 

 secure itself in the proper position to await and seize its prey. The silkj 

 which by its fineness, whiteness and close adhesion to the leaf causes it 

 to resemble the more fluid parts of the excreta, would gradually attain 



