No. 2.] MENTAL POWERS OF SPIDERS. 415 



roasted at a slow fire without the sHghtest movement — to 

 others, again, which will remain motionless as much as twenty- 

 three minutes, as I find with Chrysomela spartii. Some individ- 

 uals of the same species of Ptinus assumed a different position 

 from that of others. Now it will not be disputed that the 

 manner and duration of the feint is useful to each species, ac- 

 cording to the kind of danger which it has to escape ; therefore 

 there is no more real difficulty in its acquirement, through natural 

 selection, of this hereditary attitude than of any other. Never- 

 theless, it struck me as a strange coincidence that the insects 

 should thus have come to exactly simulate the state which they 

 took when dead. Hence I carefully noted the simulated posi- 

 tions of seventeen different kinds of insects (including an lulus, 

 Spider, and Oniscus), belonging to the most distinct genera, 

 both poor and first-rate shammers ; afterwards I procured nat- 

 urally dead specimens of some of these insects, others I 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 of the really dead 

 were as unlike as they possibly could be." ^ 



Romanes, after some discussion of the habit of feigning 

 death in higher animals, goes on to say that Professor Preyer 

 " ascribes the shamming dead of insects to the exclusive influ- 

 ence of kataplexy. . . . Now, I think it is not at all im- 

 probable that ' kataplexy ' may have been of much assistance 

 in originating, and possibly also in developing, this instinct. 

 But I desire it to be particularly noted that I only ad- 

 duce this speculation, as it were, parenthetically. I think with 

 Preyer that the shamming dead of insects is a phenomenon in 

 which the principles of hypnotism are probably concerned. But 

 if so, I regard these principles only as furnishing the materials 

 out of which natural selection has constructed this particular 

 instinct." ^ 



There seem to be no reasonable grounds for thinking that 

 spiders have any idea of simulating death, since only about once 

 in fifty times is their attitude when motionless from alarm like 

 that which they take when dead. The point at issue, then, is 



^ Darwin's Essay on Instinct ; Appendix to Mental Evolution of Animals, by 

 G. J. Romanes, p. 363. 



^ Mental Evolution in Animals, pp. 308-309. 



