404 PROCEEDINGS OF THE ACADEMY OF [May- 



or reactions. The general result was to move away slowly; sometimes 

 a few worked palps and chelicera and one lay down over the odor. 

 In this test only six specimens of Pardosa were used with the fresh 

 flowers. Time 23 to 56 sec. with an average of 32 sec. The same 

 number of specimens of L. lepida were employed with the decayed 

 flowers. Time 3 to 120 sec. with an average of 36 sec. In this as in 

 other cases 120 seconds was the limit of time without result. 



Decayed Snail (Littorina littorea). — Most moved away slowly; only 

 a few away quickly and only a few worked palps, chelicera and legs; 

 one threw up front legs and one rubbed legs together. Time for 

 L. lepida 7 to 120 sec. with an average of 61 sec. ; for Phidippus 5 to 

 120 sec. with an average of 68 sec. Thirty-four specimens were used. 



Squash Bug (Anasa tristis). — One-half moved away slowly, the other 

 half either arose quickly and moved away slowly, or moved away 

 quickly when the squash bug was held in the fingers beneath the 

 spider; a few after moving away worked legs and palps; one lay down 

 over the odor and one followed the odor when the bug was moved 

 beneath the case. Squash bugs which were caused to exhaust all 

 their secretion and had become odorless were placed in the cases with 

 the spiders, in almost every case the spider within a few minutes 

 seized and ate the bugs. When squash bugs with a strong odor were 

 placed in the cases the spiders never came within reaching distance of 

 them and usually remained away from the bugs and when the latter 

 moved toward the spiders, the araneads gave them the right of way. 

 Time for L. lepida 3 to 11 sec. with an average of 7 sec. ; for L. scutulata 

 3 to 25 sec. with an average of 13 sec; for Phidippus 3 to 6 sec. with 

 an average of 4 sec. Twenty-one specimens were employed. 



Phalangids. Most moved away slowly; the others moved away 

 quickly, or moved only slightly; one threw up front legs and two 

 turned around. The phalangids were held in the fingers beneath the 

 cases. Only occasionally when phalangids were put into the cases did 

 the araneads eat them. Time for L. lepida 3 to 25 sec. with an average 

 of 8 sec. ; for L. scutulata 5 to 55 sec. with an average of 19 sec. Thir- 

 teen individuals were used. 



Thus the general average in time for the five oils was ten seconds, 

 while for the four odors found in nature the time was thirty seconds. 

 Hence, it is evident that spiders respond to other odors besides those 

 from irritating oils, and that they have a true olfactory sense. 



To experiment with araneads collected miscellaneously without 

 regard to sex, age, time of moulting, whether parasitised or not, and 

 conditions of the weather, one obtains all kinds of variations and 

 complexities. Not enough males were used to ascertain positively their 



