DKATII AM) ITS DISGUISES. 441 



at this time upon tlie color sense, Infumata was placed in one of the boxes 

 of colored glass described in a preceding chapter, and, at intervals of one 

 hour during the day, was moved from the section in which she had set- 

 tled to another. Every time this removal was made she fell stiffly on 

 her side, drawing her legs in and remaining thus for about three minutes. 

 In experiments with her afterwards, the Peckhams found that, when 

 knocked about on a table, she would stay in the position in which she 

 fell, although this was often an uncomfortable one. Slie showed no sign 

 of life when rolled about, but jumped up at the least i>rick of a needle. 

 She never remained quiet for more than twenty-seven minutes, and never 

 absolutely motionless for so long a time as this, there being slight quiv- 

 ering movements of the legs and palps at intervals of three or four 

 minutes.^ 



The Peckhams had found no spider that would endure bad treatment 

 without showing signs of life, until they experimented on the Insular spi- 

 der. When put on a table, Insularis acted much as Infumata 

 A fepiaer j^^^j done, but had no such rigid, lifeless appearance. When 

 she was knocked or touched with the i^oint of a needle, there 

 was a convulsive twitch of the legs, though she seenied to be trying to 

 keep cjuiet. The first time she was pricked so as to puncture the skin 

 she remained motionless. But at the second puncture she ran. After- 

 wards, from both males and females of this species, the observers obtained 

 similar results, once finding an individual that did not run until the skin 

 had been punctured five times. When the needle entered the skin, there 

 was usually a twitcliing of the legs, which seemed to show that sensation 

 was present. Outside of this species the Peckhams found no spider that 

 would endure a puncture of the skin without running away, and they 

 rarely found one that would keep quiet while being handled.'^ 



Such a remarkable instinct as that of death feigning did not, of course, 



escape the observation of such an incomparable naturalist as Darwin. He 



tells us ^ that he carefully noted the simulated positions of sev- 



aiwms gj-^^gpj^ different kinds of insects, including among them a spider. 



These belonged to the most distinct genera, both poor and first 



rate sliammers. He afterwards procured naturally dead specimens of some 



of these insects, and others he killed with camphor by an easy, slow death. 



The result was that in no one instance was the attitude exactly the same, 



and in several instances the attitude of the feigners and the really dead 



were as unlike as they possibly could be. 



The Peckhams in the course of their experiments received the impres- 

 sion that the habit of keeping still after dropping must not only help the 

 spider to avoid detection, but must also make it more certain of finding 



' Ibid., page 410. ^ Ibid., page 410. 



^ Essay on Instinct, Appendix to INIental Evolution of Animals, by G. J. Romanes, 

 page 363. 



