5 o NATURAL SCIENCE. Jan., 1895. 



female, who will often rather make a meal of her suitor than a mate. 

 Consequently, to soothe her temper and reduce her to a proper frame 

 of mind, he is often driven to practice various charms and ingenious 

 wiles. The males, for instance, of some species of the Attidae or 

 jumping spiders execute fantastic dances and antics, as described by 

 Mr. and Mrs. Peckham, and, like peacocks, make a display the while 

 of whatever plumes or bright colours they possess. So that, since it 

 seems to be established that the females of the Attidae have in all 

 probability an aesthetic sense which is gratified by the sight of gaudy 

 ornaments on members of the opposite sex, there appears to be no great 

 extravagance in the supposition that the females of the species of 

 Theridium and Lephthyphantes, like the females of our song-birds, not 

 to mention nearer allies, may be charmed by the musical efforts of 

 their lovers. But whether this be the object of the stridulation, or 

 whether it be merely used as a sign of the specific identity of the 

 approaching male, the evidence indicates that it only serves its 

 possessor in his relations with the females of the same or of closely 

 allied species. 



In the second case, namely, that of Thomisoides and the Avicu- 

 lariidae, in which the stridulating organ is brought to the same state 

 of perfection in the females as in the males, the spiders themselves 

 being by analogy unable to hear, the available evidence shows that 

 the sound has nothing directly to do with the relations of one sex to 

 the other, but that it functions solely as a danger signal, warning 

 enemies to keep their distance. While, however, the signal is genuine 

 enough in the large and powerful Aviculariidae, in Thomisoides it is 

 altogether fraudulent, since this spider, which is relatively a feeble 

 animal, by aping the humming of a bee, succeeds in deluding its 

 hearers into the belief that it possesses certain dangerous qualities to 

 which in reality it has no claim. 



Lastly, since all the activities of a spider, as of every living 

 organism, are directed towards one of three ends, that is, either 

 towards procuring food or avoiding enemies or reproducing its kind, 

 it seems that the stridulating organs, so far as is now known, are 

 adapted to the furtherance only of the second and third of these three 

 vital principles. Up to the present no spider is believed to use its 

 stridulation as a means of procuring food. Perhaps, however, in the 

 future some species will be found in which the sound acts as a lure to 

 entice victims within reach. If so, we shall then be able to say with 

 some confidence that we have discovered in spiders all the purposes 

 for which sounding organs could be evolved. 



R. I. Pocock. 



