No. 2.] MENTAL POWERS OF SPIDERS. 385 



plain of this. They know how much effort the smallest ques- 

 tions require ; how the solution of small questions leads on to 

 the solution of great ones, and how barren of results it is to 

 discuss great problems before the small ones have been 

 solved." 1 



SENSE OF SMELL. 



Our experiments on the sense of smell in spiders extended 

 over two sunimers. Many of them were performed by each of 

 us separately, that one might detect the mistakes of the other. 

 Our usual plan was to hold a slender grass rod, eight inches 

 in length, in such a position that one end closely approached 

 the spider, noting what effect, if any, was produced, and then 

 to dip it into whatever scent we were using, hold it in the same 

 position, and again note the effect. We tested them in this 

 way while at rest in the web, while stalking their prey, while 

 feigning death, and under various other conditions. 



The scents used were some essential oils, cologne, and sev- 

 eral kinds of perfumes. Acetic acid, vinegar, and like materi- 

 als were avoided on account of their irritating action upon the 

 integument. 



Our first experiments were upon some tame Attidse that had 

 taken up their abode with us. They were fearless little creat- 

 ures, always ready to jump upon a finger, to catch the gnats 

 that we offered them, or to drink from a spoon. They were 

 quick to respond to any test of their sense of smell. 



For example, an Astia vittata § (var. niger) was placed upon 

 a table and the end of a clean rod was held just in front of him. 

 He promptly leaped upon it as he had been in the habit of 

 doing with our fingers, and after a moment's pause leaped again 

 to some other object, whence he was returned to the table. 

 This trial was repeated with the same result. The end of the 

 rod was then dipped into oil of peppermint and placed as 

 before. The spider instantly raised his first legs and palpi and 

 waved them in the air, this being the usual position for threat- 

 ening or defence. After standing in this way for two minutes 

 he turned slowly and walked to a little distance. Soon, how- 

 ever, he returned and took up his former position in front of 

 the rod, remaining again for two minutes, but not repeating the 



' German Psychology of To-day, p. 14, 



