No. 2.] PROTECTIVE RESEMBLANCES IN SPIDERS. 91 



inwardly discerned ' what it had observed, and to have set 

 about practicing the 'wrinkles' gained; for it first weaves a small, 

 irregular patch of white web on some prominent leaf, then a 

 narrow streak laid down towards its sloping margin ending in 

 a small knob; it then takes its place on the center of the irregu- 

 lar spot on its back, crosses its black-angled legs over its thorax, 

 and waits. Its j^ure white abdomen represents the central 

 mass of the bird's excreta, the black legs the dark portions of 

 the slime, while the web above described which it has spun 

 represents the more watery marginal part (become dry), even 

 to the run-off portion with the thickened knob (which was not 

 accidental, as it occurred in both cases), like the residue which 

 semi-fluid substances ending in a drop leave on evaporation. 

 It keeps itself in position on its back by thrusting under the 

 web below it the spines with which the anterior upper surfaces 

 of the legs are furnished."* 



In answer to the idea that the supplementing of the color 

 and form of the spider by its peculiar web almost implies 

 consciousness,! Cambridge says : 



" It seems to me, on the contrary, that the whole is easily 

 explained by the action of Natural Selection, 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 

 silk, which by its fineness, wiiiteness, and close adhesion to the 

 leaf causes it to resemble the more fluid parts of the excreta, 

 would gradually attain those qualities by Natural Selection, just 

 as the Spider itself would gradually, and probably pari passu, 

 become, under the influence of the same law, more and more 

 like the solid portion." J 



"We may repeat, in regard to this species, what Wallace has 



* On the habits of Thomlsus decipiens, by H. O. Forbes, Proc. Zool. Soc, 1883, 

 p. 586. 



t Mr. Forbes has especially disclaimed any idea of consciousness on the part 

 of the spider- 



; On two new Genera of Spiders, Proc. Zool. Soc., 1884, p. 197. 



