1875.] 505 [Emerton. 



Ox the Structure of the Palpal Organs of Male Spiders. 

 By J. H. Emerton. 



It lias long been known that the copulation of spiders Is performed 

 by the introduction of peculiar organs on the ends of the palpi of the 

 male into openings near the outlet of the ovaries in the abdomen of 

 the female. 



Treviranus, who discovered the testes of Aranea domestica in 

 1812, thought that the palpal organs were used to excite the female, 

 or to open the passage to the ovaries, and that the true copulation 

 took place afterward, by the contact of the openings in the abdomens 

 of the two sexes. 



Lyonet, in Memoires du Museum d'Histoire Naturelle, 1829, de- 

 scribed and figured the palpal organs of three species of spiders, and 

 showed clearly that they were furnished with a tubular process, 

 which he called the penis, with an opening at the end. In the pal- 

 pal organ of Aranea domestica, he showed that a fine duct passed 

 from this orifice toward the base of the organ. 



Menge, in 1843, in his memoir on the habits of spiders, Schriften 

 der Naturforschenden Gesell. Danzig, gave the first account of the 

 whole process of copulation. He saw the male drop the semen from 

 the opening in his abdomen, on the web, and then take it up by his 

 palpi, and afterward copulate in the usual way. Menge considered 

 the essential parts of the palpal organs to be a hard process (Ein- 

 dringer), the tubular structure of which he does not mention, and a 

 rough membranous appendage (Samentrager), which wipes up the 

 semen from the web and carries it to the female opening. This view 

 of the structure of the palpal organ he repeats in the introduction to 

 his monograph of the spiders of Prussia, in 1866. 



In 1851, Dr. W. I. Burnett examined the palpal organ of Agelena 

 ncevia Hentz, and found a duct leading from an opening at the end 

 of the penis to a capsule at the base of the palpal organ. This he 

 describes in the Proceedings of the Boston Society of Natural His- 

 tory, Vol. IV, and in a note in his translation of Siebold's Anatomy 

 of the Invertebraia. 



In 1868, C. O. Hermann published in the Proceedings of the 

 Zoological-Botanical Society of Vienna, a paper on the sexual 

 organs of Epelra quadrata, in which he asserts that the palpal organ 

 not only has a hollow penis, but that a tube passes from it through 

 the thorax to the testes in the abdomen of the spider. 



