128 PROCEEDINGS OF THE ACADEMY OF [Jan., 



man, Lendl, Lesser, McCook, Menge (in numerous species), the Peck- 

 hams, Ritsema, Seidel, Treat, Walckenaer, Westberg. These confirm- 

 atory observations, embracing species of all the larger araneid families, 

 make it very probable that in all modern Araneids the male transfers 

 the sperm to the female by means of his palpi. Two writers have com- 

 bated this conclusion: Treviranus, who first discovered the testes of 

 spiders and, finding no organic connection between these organs and 

 the palpi, maintained that the application of the male palpi to the 

 epigynum is probably not real copulation, but rather a preliminary 

 act of stimulation; and Cambridge, who states he observed two indi- 

 viduals of a Lycosa in coition, with their genital apertures in apposition. 

 In \dew of the numerous observations on this act in Lycosa, I have no 

 hesitation in stamping Camljridge's assertion as erroneous. In all 

 the families where the act has been seen, accordingly, the palpal 

 organs are the transmitters of the semen. 



Now though Treviranus showed conclusively that there is no organic 

 connection between the testes, or the vasa deferentia, and the peculi- 

 arly modified palpal organs, some later writers, particularly Cambridge 

 and Herman, insisted that there must be some such tubular connection, 

 in order to explain the presence of spermatozoa in the palpal organs. 

 The results of all other anatomists, however, have corroborated 

 Treviranus, and Menge discovered, first in the year 1843, how the 

 sperm is brought from the genital aperture into the tubular appa- 

 ratus of the palpal organs. In that paper of 1843, an arachnological 

 classic, he described the process for Linyphia triangularis and Agalena 

 labyrinthica, showing that the male constructs a little silken bridge 

 or "Steg," deposits a drop of sperm from his genital aperture upon it, 

 then applies his palpal organs alternately to the drop until they have 

 absorbed it all; then, and not till then, is the male ready for copulation. 

 This process of charging the palpi with sperm, which I have termed 

 here "sperm-induction," was described by Menge later also iovTapi- 

 nopa longidens, Agalena similis and Micrommata virescens. The only 

 other writers who have described this process are Black wall (1863, 

 in Agalena labyrinthica), Ausserer (1867, in Dictyna henigna and Liny- 

 phia triangularis), Bertkau (1875, 1876, in Philoica domestica, Linyphia 

 montana and Cluhiona comta), Westberg (1900, in Linyphia triangu- 

 laris). To these may be added my present observation on Lycosa 

 stonei, L. ocreata pulchra, Tegenaria derhami, Theridium tepidariorum 

 and Dictyna volupis (here seen twice). Hasselt was unable to see this 

 process himself, and on that account doubted whether it is of general 

 occurrence among spiders. 



