170 ARACHNIDES. 



time before they yield to their wishes, and when this is the 

 case they quickly and repeatedly apply the extremity of their 

 palpi to tlie inferior surface of the abdomen, protruding at 

 each time and as if by a spring, the fecundating organ con- 

 tained in the button formed by the last joint of those palpi, 

 and insinuate it into a sub -abdominal slit, near the base and 

 between tlie respiratory orifices; after a moment's interval the 

 same act is repeatedly performed. Such is the mode of co- 

 pulation of a small number of species belonging to the Orbi- 

 tekc. It is impossible to avoid feeling the most lively interest 

 in reading what has been written upon this subject by that 

 learned naturalist, who of all others has most profoundly stu- 

 died these animals, the celebrated VValckenaer, member of the 

 Acad, des Inscriptions et Belles-lettres. The apparatus of 

 the male organs of generation, or at least of what are consi- 

 dered as such, is usually highly complicated and very various; 

 it consists of scaly pieces, more or less hooked and irregular, 

 and of a white fleshy body, on which sanguineous looking 

 vessels are sometimes perceptible, which is considered as the 

 fecundating organ, properly so called ; but in the Arachnides 

 with four pulmonary sacs, and in some belonging to the divi- 

 sion where there are but two, the last joint of the palpi of the 

 males only exhibits a single horny piece in the form of a hook 

 or ear- picker, without the smallest visible opening. Although 

 MuUer and others were mistaken when they placed the male 

 organs of certain Entomostraca upon two of their antennae, 

 it is very certain that the parts considered as analogous to 

 them in the Araneides, are very different from those observed 

 on the antennae of those Crustacea, and that if we refuse to 

 admit of their exercising this function, it is impossible to con- 

 ceive of their use(l). 



According to the experiments of Audebert, who has given 

 us a history of the Monkeys worthy of the talents of that 

 great painter, it is certain that a single fecundation is sufficient 

 for several successive generations, but that with them, as with 



(Ij They must at nil events be ofgans of excitation. 



