OCR Text |
Show 170 AH.ACHNlDBS. time before they yield to their wishes, and when this is the case they quickly and repeatedly apply the extremity of their pal pi to the iuferior surface of the abdomen, protruding at each time and as if by a spring, the fecundating organ contained in the button formed by tl.te last. joint of those pal pi, and insinuate it into a sub-abdom1nal sbt, near the base and between the 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. telre. 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 studied these animals, the celebrated Walckenaer, 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 Arachnid~ 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. Althoug~ Muller and others were mistaken when they placed the male organs of certain Entomostraca upon two of their antennre, it is very certain that the parts considered as analogous to them in the Araneides, are very different from those observed on the antennre 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, hut that with them, as witl1 ---------- -------- .. ~-- ( t ) They must at all events be organs of excitation. PULMONAHIJE. 171 11 Insects and other analogous classes, the ova are sterile ~vithont a union of the sexes. Their. nuptial season in France lasts f1 , 001 the latter end of summer t1ll the beginning of October. The ova fit•st laid are frequently hatched before the termination of autumn : the others remain in statu quo dut·ing the winter. The females of certain species of Lycosa have been observed to tear open the egg-sac when the young ones were about to issue from the ovum. The latter then mount on the back of their mother, where they remain some time. Other female Araneides carry their cocoons under the abdomen, or remain ncar them and watch them. The two posterior feet of some of the young ones are not developed until several days after they have been hatched. Some, during the same period, Jive together, and ap1)ear· to spin in common. Their colouring is then more unifor~, and the young naturalist may easily err in multiplying their species. One of our collaborators for the Encyclopedic Methodique, M. A. Lepelletier of Saint-Fargeau, has observed that these animals, as well as the Ct·nstacea, possess the faculty of reproducing a lost limb. I have ascertained that a single wound from a moderate sized Araneid will kill our common Fly in a few minutes. It is also certain that the bite of tho~e large Araneides of South America, which are there called Crab-Spiders, and are placed by us in the genus Mygale, kills the smaller vertebrated animals, such as Humming-Birds, Pigeons, &c., and produces a violent fever in Man; the sting of some species in the south of France has even occasi~nally proved fatal. We may therefore, without believing all the fabulous stories of Baglivi and others respecting the bite of the Tarantula, mistrust the Araneides, and particularly the larger ones. Various insects of the genus Sphex, Lin., seize upon these Spiders, pierce them with their sting, and transport them into holes where they have deposited their eggs, as a sourc"e of food for their young. Most of them perish in winter, but there are some which live several years-such are the My· gales, the Lycosa, and probably several others. Although Pliny states that the genus Phalangium is unknown in Italy, |