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Show 204 AH.ACHNIDES. The abdomen is composed of twelve annuli, those of the tail included• the first is divided into two pat·ts, of which the anterior bears th: sexual organs, and the other the two combs. These appendages are composed of a principal, narrow, elongated and articulated piece movable at base, and furnished along its inner side with a suite of little hollow laminre, united to it by an articulation, that are nar. row, elongated, parallel, and similar to the teeth of a comb; their number is more or less considerable according to the species· it varies to a certain extent, and perhaps with age, in the same ;pe· cies. No positive experiment has yet determined the use of thm appendages. The four following annuli have each a pair of pulmo. nary sacs and stigmata. Directly after the sixth, the abdomen becomes suddenly narrowed, and the remaining six, under the form of joints, compose the tail. All the tarsi are alike, and consist or three joints, with two hooks at the end of the last. The four last legs have a common base, and the first joint of the hip is soldered; the two last are even partly fixed against the abdomen. The two nervous cords, proceeding from the br·ain, unite at in· tervals and fot·m seven ganglions, the last of which belong to the tail. In all other Arachnides, there are never more than three. The eight stigmata open into as many white bursre, each contain· ing a great number of very slender, smalllaminre, between which it is probable that the air passes. A muscular vessel extends along the back, and communicates with each bursa by two branches(!); it also distributes vessels to every part of the animal. The intestinal canal is straight and slender. The liver is composed of four pairs of glandular clusters, which pour their humour into the intestine at four points. The male has two copulating organs arising near the combs, and the female has two vulvre. The latter open into a matrix consisting of several inter-communicating canals, which in the proper period are found filled with living young ones; the testes are also formed of some anastomosing vessels(2). These Arachnides inhabit the hot countries of both hemispheres, live on the ground, conceal themselves under stones and other bo· dies, most commonly in ruins, dark and cool places, and even in houses. They run with considerable swiftness, curving their tail over their back. They can turn it in every direction, and use it for the purposes of attack and defence. With their forceps they seize (1) See our preceding remarks on the circulation of the Arachnides puJmo· nari;e. (2) For the anatomy of the Scorpion, see Treviranus, Marcel de Serres, and Leon Dufour, Journ. de Phys., June 1817. PULMON A RTJE. 205 0 'sci and various insects, Carabici, Orthoptera, &c., on which hnt feed, pierce them with their sting by directing it forwards, and they pass their prey through their chelicerce and jaws. They are 1 ~icularly fond of the eggs of Spiders and of Insects. paThe wound occasioned by the sting uf the europmus is not usually dangerous. Tha~ of the Scorpion of Souvignarg~es, of Mauperti~s, fthe species wh1ch I have named Roussatre (occ~tanus), and wh1ch ~s larger than the preceding one, according to the experiments of Dr Maccary courageously tried upon himself, produces serious and alarming symptoms; the older the animal the more active seems to be the poison. The remedy employed is the volatile alkali, used externally and internally. Some naturalists have asserted that the European species produce two generations in the year. That which appears to me to be the most unequivocally ascertained, occurs in August. The female in coitu is laid on her back. According to Maccary she changes her tegument previous to the production of her young. The male experiences a similar alteration at the same epoch. The young are produced at various intervals. The mother carries them on her back for several days, during which time she never leaves her retreat, and watches over them for a month, when they are strong enough to establish themselves elsewhere and provide for their subsistence. Two years are required to qualify them for continuing their species. Some have eight eyes; they form the genus Buthus of Leach. S. afer, L., Fab.; .llfrican Scorpion, Rres., Insect., 3, lxv; Herbst., Monog. Scarp., 1. Five or six inches long, and of a blackish brown; the forceps large, cordate, rough and somewhat hairy; anterior edge of the thorax deeply emarginate; thirteen teeth to each comb. From the East Indies, Ceylon. S. roussiltre; S. occitanus, Am or.; S. tunetanull, Herbst. Monog. Scarp. III, 3; Buthus occitanus, Leach, Zoo!. Miscell., cxliii. Yellowish or reddish; tail rather longer than the body, · with elevated and finely crenulated lines. Upwards of twentyeight teeth-fifty-two to sixty-five, Maccary-to each comb. From the south of Europe, Barbary, &c.-Very common in Spain. The others have but six eyes; they compose the genus Scorpio, properly so called, of the same naturalist. S. europmus, L., Fab.; Herbst. Monog. Scarp., III, I, 2. Brown, more or less dark; legs and last joint of the tail paler or yellowish; forceps cordate and angular; nine teeth to each comb. From the extreme southern and eastern departments of France. |