<^319. 



THE ARACHNOIDAE. 



395 



defefent canals to the base of the abdomen where, between the two pulmo- 

 nary sacs, there is a genital opening in a small horny plate. This opening 

 is only a simple transverse fissure which, in copulation, does not come in 

 contact with the vulva of the female. These animal^ always use their 

 hollow, spoon-shaped palpi, which often have a very complicated structure. 

 They are filled with sperm and applied to the entrance of the vulva. For 

 this purpose, the last article of the palpi, which is always hollow and much 

 enlarged, contains a soft spiral body terminated by a curved, gutter-like, 

 horny process. Beside this, there is an arched, horny filament, and 

 several hooks and other appendages of the most varied forms. These 

 appendages are protractile, and serve, some to seize the female, and others 

 as conductors of the sperm. <**' 



With the Scorpionidae, each of the two testicular tubes forms a loop 

 enveloped by the substance of the liver, and connected with its mate by two 

 transverse canals. The anterior border of each of these loops sends off a 

 short Vas deferens which opens at the base of the abdomen, receiving in 

 its track two caeca of unequal length. Of these, the longer contains a 

 granulo-vesicular substance, and is, perhaps, an accessory gland ; while the 

 shorter, from the character of its contents, is evidently a Vesicula semi- 

 Tialis.'-^^ A deeply crenated, small papilla projects out of the genital 

 orifice, and, as it is wanting with the females, may be regarded as a 



^ For a long time, the excretory point of tlie J^'osa 

 defer entia was undetermined, because the two 

 sexes of these animals had never been seen to place 

 in contact these genital orifices during copulation. 

 But when it was discovered that only the palpi of 

 the males touch the vulva, the excretory ducts of 

 the testicles were sought in these palpi. It is only 

 recently, however, that it has been perceived, that 

 with these animals, as with the Libellulidae (see my 

 memoir in Germar''s Zeitsch. f. d. Entomol. II. p. 

 42-3), the copulatory organ and the Vesicula semi- 

 nalis are entirely removed from the male genital 

 orifice. In order to be convinced that the applica- 

 tion of the male palpi against the female vulva 

 constitutes really the act of copulation, it is only 

 necessary to examine the palpi under the micro- 

 scope and compress them. From the last article a 

 large quantity of sperm will be seen to escape. 

 Then again, after copulation, the Receptacula sem- 

 inis of the females will be found filled with the 

 fluid. The form of the palpi with the males varies 

 almost Infinitely according to the genera and spe- 

 cies. They are very simple and slightly swollen 

 with Clubiona and Lycosa, while, with Epeira, 

 Tegenaria, Linyphia, Micryphantes, Sa/ticus, 

 Argyroneta, itc, their last article is so comphcated 

 that the most minute description would be inade- 

 quate in giving an exact idea of it ; see the figures 

 of Lyonet, loc. cit. p. 383, PI. XIX. XX.; Trevi- 



ranus, Bau d. Arachn. p. 37, Taf. IV. fig. 35- 

 37 ; Brandt, Mediz. Zool. II. p. 87, Taf. XV. fig. 

 1 ; Savigny, Descript de I'Egypte, PI. I.-VII. ; 

 Menge, loc. cit. p. 35, Taf. III. fig. 13-27. 



Treviranus (Bau d. Arach. p. 33) has made an 

 exposition of the older opinions of Lister, Lyonet, 

 Clerk, and Degeer, on the copulation of these ani- 

 mals ; but he regarded the act as only a prelude 

 for exciting the sexual desu'es, and which would be 

 followed by a real copulation, consisting of the con- 

 tact of the male and female genital orifices. More- 

 over, Treviranus had never observed this last act. 



The more recent observers, such as Duges (Ann. 

 d. Sc. Nat. VI. p. 187), Menge (loc. cit. p. 36), and 

 Blackwall (Annals of Nat. Hist. XV. p. 225), have 

 naturally only confirmed the views of the older nat- 

 uralists. According to Menge, the males of Lin- 

 yphia and Agelena evacuate a drop of sperm from 

 their genital orifice, which is then received and 

 absorbed by the last article of their palpi.* 



9 For the male organs of the Scorpions, which 

 have been very imperfectly described by Trevira- 

 71US (Bau d. Arachn. p. 22, Taf. I. ti'.:. 11), see 

 Meckel (Beitrftg. loc. cit. p. 114, Taf. VII. fig. 14), 

 Serres (loc. cit. p. 89) and Mailer (loc. cit. p. 59, 

 Taf. I. fig 8). I have seen distinctly with living 

 individuals of Scorpio europaeus, spermatic par- 

 ticles in motion in the small caeca which I have 

 called the seminal vesicles. 



*[§319, note 8.] I have made a microscopic 

 examination of this curious palpus-structure in 

 connection with the general structural relations of 

 the mternal genital organs, in some of the common 

 Araneae (Tegenaria, Agelena, &c.) where this 

 formation is most marked. In Agelena, the pecu- 

 liar, corkscrew-like, horny process, situated in 

 the last, spoon-shaped article of the palpus, con- 

 tains a canal throughout, which commences in 

 a kind of receptaculum at the base of the pro- 

 cess. This receptacle is filled with the peculiar 

 granule-like bodies mentioned above (Note to § 



316, note 7). As the most repeated and careful 

 examinations showed no spermatic particles in this 

 palpus-capsule, I was led to advance the view that 

 the palpi were only excitatory and not intromittent 

 organs, in the copulatory act (see Proceed. Boston 

 Soc. Nat. Hist. IV. 1851, p. 106). But the question 

 is still open, and especially as some recent investi- 

 gators of the economy of these animals have observed 

 facts that would indicate the intromittent function 

 of these organs ; see particularly, Blackwall, .\nn. 

 Nat. Hist, passim, for several years past. — Ed. 



