No. 2.] MENTAL POWERS OF SPIDERS. -i^^c^ 



and, when they were returned to her, spun a web over them in 

 the corner of the box in which they were placed. Of all the 

 spiders that we experimented upon, the little TJieridium glo- 

 bosnm Hentz had the best memory for her cocoon. We took 

 her from her web and returned her to it after fifty-one hours. 

 She at once went to the eggs and touched them with her legs. 

 She then left them to improve her house, every now and then 

 running back to see if they were safe. After she had arranged 

 her household to her satisfaction she settled down near them. 



Several species of Attidae and Thomisidae did not remember 

 their cocoons for twenty-four hours ; yet these spiders, although 

 they do not carry the egg-sack about with them, remain near it 

 for from fifteen to twenty days. 



SENSE OF SIGHT. 



We were much surprised in the earlier experiments to find 

 how entirely the Lycosidae depended upon touch in finding 

 their cocoons. We had almost concluded that their sense of 

 sight was but little developed. To quote from our notes : — 



July 9. — Took the cocoon from P. montaniis Emerton. 

 She seemed much disturbed, and hunted around very eagerly; 

 several times she passed close to it, and her eyesight must have 

 been dull, or she would have seen it. At last she chanced to 

 touch it with one leg, when she at once perceived it and laid 

 hold of it with her fakes. After a little we repeated the experi- 

 ment, but now the cocoon was suspended just high enough to 

 allow her to pass beneath, without touching it. She ran about 

 seemingly very anxious to find it, but although she several times 

 passed directly under the cocoon she did not discover it. 



During the past summer we took away the eggs from a num- 

 ber of these spiders, and, placing them upon paper from one to 

 two inches away from their cocoons and looking toward them, 

 traced along the course they ran in looking for them. The 

 tracing on the next page illustrates the persistency of the spider 

 in hunting for her egg-sack, and how little she was aided by the 

 sense of sight in recovering it. 



The spider, Pardosa pallida, was some ten minutes in making 

 the various turns before she reached the cocoon. Three times 

 she came very close, and when, at last, she found it, she had 



