862 THE AMERICAN NATURALIST. [Vol. XXXVIII. 



mately 2300 vibrations was suspended above the hearing cage 

 and struck repeatedly with a metal hammer. Eight fresh speci- 

 mens were placed successively in the cage but no spider made 

 any motion that could be interpreted as a response to the 

 sound. 



Again, a mason's trowel was held near the cage and struck 

 several times with a metal bar producing a loud, crashing noise, 

 but the spiders made no motion whatever. 



These experiments were undertaken to ascertain first whether 

 the si)iders ])os.sessed the sense of smell and second to localize 

 the same, if possible, in case it was iound to exist. The experi- 

 ments were made mostly upon Pardosa mcrcurialis. 



Two classes of the essential oils were used as tests. Those 

 of the first class were the non-irritants, lavender, cedar, winter- 

 green, almond, juniper-berries, bergamot, cassia and cloves ; of 

 the second class, those irritants that will cause sneezing in man 

 were oils of mustard and black pepper. The results from the 

 use of the two irritating oils were essentially the same as those 

 for the stronger oils of the non-irritating class, and the reac- 

 tions wcie the same in every case only that they were more 

 mu-nsifictl witli the oils of stronger odors. 



1 Ik- hcaimg ( age was used for the smell experiments. 



^mall i^lass lod.s were dipped into the oil and the drop that 

 adhci.'d was lu ld immediately below the cage. In each case 

 ''I ^^■^■'11^(1 repelled to a greater or less degree corre- 

 al • ''111,^ to the strength ot the oil, and in no in.stance was it 

 • '^'1 '"uaid the stimulus. The males and females gave 

 > 111. >ame 1 espouse, thus showing that neither .sex has a 



"^^ ' *-""^i":is'''s weie (I) turning away and moving as far as 

 '""^^ '"'•'I. (2) vibratory movements of the palps 

 '^"^ iiM'idihle.. , ^ ) laismg each leg as the oil is applied beneath 

 1» -nic ui.e. all the responses were given to a .single 

 stimulus \\\ (,rh.T< ,.nK 1 • • , ^ 



J, ' '^'"-'^ <'ni\ one, or a combmation of either two. 

 '^p^iiments were made lirst on unmutilated specimens to 



