33^ I'KDAl. .\(»SI-; IX TRAI'-DOOK Si'lDKKS. 



slu^e^^ish creatures, remaining quite motionless for Ion"- ])eri()ds, 

 thou,g^h when disturbed they would run away with considerable 

 speed, never making- any attempt to bite. In testing their ol- 

 factory p<nvers, a pair of ladies' hatpins was employed, one of 

 them, as a control being brought near to the si)ider at the jioint 

 which it was desired to test, when, on finding no res])onse, the 

 other, bearing a droplet of odoriferous licjuid on its ])ointed end, 

 was brought forwards in a similar way. due care being taken to 

 avoid actual contact with the skin or hairs of the creature. The 

 results were very striking. Every time the scented jiin was 

 brought near to the tip of a leg. within a few seconds that leg 

 was raised or withdrawn ; sometim.es the creature as a whole 

 moved away. So far as I could judge, the s(^ft skin u\ the 

 abdomen and the middle joints of the leg were not receptive 

 to the stimulus, and. indeed, no part of the body except the 

 tips of the legs was found to be sensitive ; it seemed impracti- 

 cable, hoAvever. to test the sensitiveness of the sternum. Th6 

 scents employed were the tnls (^f clo\es. eucalyptus and citron- 

 ella. also ammonia solution. The citronella oil proved most ef- 

 fective, clove oil least so. Of the four pairs of legs, the first 

 and second pairs were clearly most sensitive, judging from the 

 time involved in the reaction, whilst the fourth j^air was least 

 sensitive. All the odours employed were re)iellent in their 

 action. 



One morning, choosing a strong specimen. I cut off the end 

 of the first leg of the right side, at about the midpoint of the 

 metatarsus (penultimate joint) ; by evening the creature seemed 

 fairly active, and all his legs responded in turn to the citronella 

 test except only the injured one, from which no response what- 

 ever was obtained. The ex])eriment was subse(|uently repeated 

 with another specimen, but still with no res])onse in the injured 

 leg. When the aminitation was made at the midijoint of the 

 tarsus (end-joint), a dehnite though feeble res]K)nse to a scenterl 

 needle was obtained on the following day, shewing that the 

 olfactorv organ is not confined to the distal half of the tarsus. 



Similar tests were made with adult females of the same 

 species, also taken at Alicedale, and Mr. Cruden inde|)endently 

 experimented with other female specimens. Curiouslv enougii, 

 they api)eared to lie altogether insensitive to the odours em])loved. 

 As yet I am unable to sa\- with certaint\- what structures 

 are concerned with this olfactory sense on the feet of the male 

 Stasiinof^iis. Microscopical examination suggests two possibili- 

 ties. The olfactory organ may lie in the hairs of the scopula, a 

 tei-m emi)loyed for the pad of fine hairs found on the lower 

 and lateral surfaces of the tarsi and the terminal i)ortit)n of the 

 metatarsi. These hairs, when examined under a high i)owef, 

 arc seen to be essentiallv different from the several kinds of 

 hairs which clothe the oihcr segments of the leg and of the abdo- 

 men ; the latter are all linel\- ])otnied, their tips being solid ruid 

 stroiigK chitinoiis; the s(.-Mpnlar hairs, on the otjier hand, are 

 truncated or e\en fmni(T^h;i])ed at the tip^, where ai)i)areiuly 



