ORDER PULMOXARIyE. 389 



appears to consist but of a simple dorsal vessel, and also rela- 

 tively to the testicles and the spermatic vessels, on which he 

 has afforded no information. 



The dorsal region of the abdomen in many arane'ides, espe- 

 cially in those which are smooth or but slightly furnished with 

 hair, presents deep or umbilical points, the number and dis- 

 position of which vary. M. Dufour has ascertained that those 

 little orbicular depressions were determined by the attach- 

 ment of the filiform muscles which traverse the liver, and 

 which he has also observed in the scorpions. 



The pulmonary cavities, to the number of one or two pair, 

 are indicated externally by so many yellowish or whitish 

 spots, placed near the base of the belly, immediately after the 

 segment, which, by means of a fleshy thread, unites the abdo- 

 men with the thorax. Each pulmonary pouch is formed by 

 the superposition of a great number of triangular leaflets, 

 white, and extremely slender, which meet together around the 

 stigmata, which always answer in number to the pulmonary 

 sacs. Where there are four of them, a sort of fold, or vestige 

 of a ring, existing even in those where there are but two, and 

 placed immediately after them, forms a line, which separates 

 the two pairs. 



The female araneides have two very distinct ovaries, lodged 

 in a sort of capsule formed by the liver. Not fecundated, they 

 appear of a spongy tissue, as it were flaky, and constituted 

 by the agglomeration of rounded corpuscles, scarcely percep- 

 tible, which are the germs of the eggs. In proportion to the 

 progress of fecundation, the cluster formed by these eggs 

 becomes less compact ; and we find that they are inserted 

 laterally on many canals. Their great analogy with the 

 ovaries of the scorpion causes the same observer to presume 

 that they form meshes, terminating in two distinct oviducts, 

 which open into one and the same vulva. The configuration 

 of the latter varies much : sometimes it is a longitudinal bila- 



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