128 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



VIII. 



It is now generally believed by araneologists that the digital joint or 

 bulbus of* the palp is the copulative organ of male spiders. We are 



indebted to the careful observations of Menge 1 for the discovery 

 Use of O f t ne me thod by which the male transfers the sperma from his 



sexual aperture to his palps, and so, through the palps, to the 



vulva of the female. Blackwall, however, with that keenness of 

 observation and judgment which characterized this distinguished English 

 naturalist, independently observed the process. 2 A male Agalena labyrin- 

 thica confined in a phial spun a small web, and among the lines of which 

 it was composed he perceived that a drop of milklike fluid was suspended. 

 He had not observed how it was deposited, but saw that the spider by the 

 alternate application of his palpal organs speedily imbibed the whole of 

 it. The conclusion which he derived from this circumstance was to con- 

 firm the acute suspicion of M. Duges that the palpal bulb alternately 

 performs the office of an absorbing syphon and an organ of ejection. 3 

 The fact first made known by Menge has been abundantly confirmed by 

 Ausserer 4 and Professor Bertkau, 5 and later by Mr. F. M. Campbell," and 

 in part by the author. 7 



The former belief that the testes have their outlet into the palp has 

 now very few, if any, advocates. Those who have most carefully studied 



the anatomy of spiders, from the earliest to the latest students, 8 

 1 have found that no connection whatever can be traced between 



OI TSu0S 



' the organs which prepare the spermatic fluid and the palps, and 

 that the testes are far from these latter organs, on the under side of the 

 abdomen, near its anterior extremity, in a position corresponding to the 

 female vulva. The little slit there, on which the efferent ducts of the 

 testes have their orifices, may sometimes be seen with the naked eye or a 

 simple magnifying lens. Under such circumstances one may well ask with 

 Thorell, 9 what is more natural than to suppose that the sperma, previous 

 to coition, is in some way or other transferred to the intromittent organs, 

 the palps? That this transmission always takes place in the manner 

 directly observed by Menge in the case of Agalena and Linyphia is indeed 



1 Ueber die Lebenweise d. Arachn. Naturf. Gessellsch. in Danzig, IV., I., pages 39-41 

 (1843) ; Preuss. Spinn. f. inst. I., page 306 (1866). 



2 Journal Proceedings Linn. Soc. Zool., VII., pages 157, 158. 



8 Observ. sur lea Aran., Ann. d. Soc. Nat. Ser. Zool., VI., pages 189, 190. 

 * " Beobactungen iiber die Lebenweisse," etc., Zeittchr. Ferdinandeums, 1867. 



5 "Ueber den Generations apparat der Arachniden," Arch. Nat. Gesch., 1875, page- 254. 



6 " Pairing of Teg. guyonii," Linn. Soc. Jour. Zool., XVI., 163. 

 ' See Vol. II., page 41 and page 73. 



8 TREVIRANUS, Ueber d. inneren Bau d. Arachn., page 77, tab. iv., Fig. 33 (1812) ; MK.V;K 

 Preuss. Spinn., I., pages 32, 33 (1866). 



9 Synonyms Europ. Spid., page 593. 



