ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 575 



y. Araclinida. 



Mental Powers of Spiders.*— Mr. G. W. and Mrs. E. G. Peckham 

 liave made a large number of observations on the mental powers of 

 spiders. 



Sense of Smell. Three species {Argyroepeira Jiortorum, Dolomedes 

 tenehrosus, and Herpyllus ecdesiasticus) did not respond to the tests. 

 In all other cases it was evident that the scent was perceived by the 

 spiders. 



Sense of Hearing. All the Epeirids responded promptly to the tests, 

 being evidently alarmed by the sound of the tuning-fork, but the spiders 

 that make no web gave not the slightest heed to the sound. It is 

 suggested that this difference may be partly explained by the difference 

 in the feeding habits of the two groups. 



Maternal Emotions. Notwithstanding many efforts the authors never 

 found one of the Lycosidge that was constant in her affection for as long 

 as forty-eight hours. A female of Clubiona pallens, however, remembered 

 her eggs for this length of time, and when they were returned to her, 

 she spun a web over them in the corner of the box in which they were 

 placed. Theridium glohosum had the best memory for her cocoon ; after 

 fifty-one hours' absence she at once went to the eggs, and touched them 

 with her legs. Several species of Attidte and Thomisidas did not 

 remember their cocoons for twenty-four hours, although these spiders, 

 which do not carry the egg-sac about with them, remain near it for 

 from fifteen to twenty days. 



Sense of Sight. It is well known that spiders are supposed not to 

 see their own cocoons at a very short distance ; the authors explain this 

 by describing how the cocoon is made without its maker ever even 

 seeing it, and they come to the conclusion that the use of the sense of 

 touch is necessary for the spider to be able to perceive the cocoon. 



Colour Sense. There is a marked preference for red, and there can 

 be no doubt that some spiders have a distinct colour sense. 



Feigning Death. The authors consider the gist of the matter to be 

 this ; certain EpeiridaB, when alarmed, drop from the web and remain 

 quiet for a longer or shorter time, their concealment being greatly 

 assisted by the protective colouring which is present to some extent in 

 nearly all of them. This amounts to nothing more than that when 

 another spider runs to a place of safety, an Epeirid drops a greater or 

 less distance to a place of safety. Both then remain quiet, unless dis- 

 turbed, in which case the first spider trusts to its powers of running, 

 while the Epeirid often (but not invariably) finds its best chance of 

 safety in keeping quiet unless it is actually abused ; the habit of keeping 

 quiet also insures the spider's safe return to its web when the danger is 

 over. There is no need to call in " kataplexy " to explain the origin or 

 development of a habit which can be so easily explained by natural 

 selection alone. The habit is found in its greatest development among 

 the comparatively sluggish Epeiridee, whereas it is badly developed or 

 lacking in the running and jumping spiders which are able to move with 

 astonishing rapidity. 



Mistalces of Spiders. Spiders were found to be much less clever than 

 supposed, in regard to the recognition of their cocoons, little pith-balls 

 leading them quite astray. If allowed a choice a Lycosid will select the 



* Journ. of Morphology, i. (1887) pp. 383-il9. 



