388 PECKHAM. [Vol. i. 



up, as though it had been a fly. After she had worked at it for 

 two minutes, and had wrapped it up very thoroughly, it was 

 taken away as gently as possible, whereupon she began to put 

 the tips of her legs between the palpi and falces. We have seen 

 a male of this species go through the same motions, after catch- 

 ing an ant in his web, and then losing it. So decided a re- 

 sponse to the dry heliotrope seeming to show an unusual 

 sensitiveness, the rod was again dipped into heliotrope, and 

 held, as soon as it was dry, first, near a male, and then near 

 three females of labyrintJica. All jumped at it and grasped it, 

 seeming puzzled, but returned to the web without binding it up. 



We now took a clean, unscented rod, and with it gently 

 touched, in turn, the five spiders already experimented upon. 

 Each of them clasped it, examined it for a moment, and then 

 returned to the web, their action being not very unlike that of 

 the second, third, fourth, and fifth spiders experimented upon 

 with the dried heliotrope, but showing less excitement of 

 manner. 



The dried heliotrope was then again offered to the first 

 spider. She began to bind it up as before ; then stopped and 

 rubbed her palpi violently up and down upon it for some time ; 

 then rubbed it hard with all her legs, excepting the fourth pair; 

 then again with her palpi. She seemed to be trying to get 

 something off. After five minutes, while she was still at work 

 in this way, the rod was removed. 



It may be noted, in connection with this experiment, that we 

 have repeatedly noticed, among spiders of the same species, 

 great differences of degree in their sensitiveness to odors. 



The position of the organ of smell in spiders is unknown. It 

 has been generally supposed that it existed in the palpi, 

 although Robineau-Desvoidy located it in the mandibles.^ 



' "As to spiders, it is not certainly known whether, and to what extent, they share 

 in the sense of smell. Robineau-Desvoidy (1842) said that their sense of smell is 

 very well developed and localized in the mandibles, but Ferris placed them in the 

 lowest rank of arthropods; though he remarks on the sensibility of their palpi to 

 smells." — A. S. Packard's abstract of Kraepilin's criticisms on the works of writers on 

 the olfactory organs of arthropods. Am. iVat., Vol. XXI., p. 182. 



" Ferris accorde aux palpes une faible olfaction a courte distance. II fait remarquer 

 que les araneides, les seuls articules qui n'ont pas d'antennes, paraissent avoir I'olfac- 

 tion tout a fait rudimentaire. . , . Enfin Ferris et Comparette croient que les palpes 

 servent a I'olfaction a cote des antennes." — Auguste Forel. Sensations des Jnsectes, 

 II. Reciieil Zoologique Suisse, Tome IV., No. 2, pp. 190, 192. 



