. A manual of zoology. Zoology. Fig. 293. Fig. 293. Fig. 292.âHirndo medicinalis, medicinal leech. (After Leuckart.; a. anterior end with three .laws (fc); 5, a single jaw with its muscles. Fig. 298.âNervous system, blood-vessels, sexual organs, and nephridia of a leech, ventral view, h, testes; hb, urinary bladder; Ig, lateral blood-vessel; 71. ventral nerve cord; nh, epididymis; oi', ovary; p, penis; sc, nephridia; n, uterus and vagina; u(/, vas deferens: I'y, ventral blood-vessel. testes (//), the ducts of which unite to form a vas deferens on either side (ed). These pass forward, form by c
. A manual of zoology. Zoology. Fig. 293. Fig. 293. Fig. 292.âHirndo medicinalis, medicinal leech. (After Leuckart.; a. anterior end with three .laws (fc); 5, a single jaw with its muscles. Fig. 298.âNervous system, blood-vessels, sexual organs, and nephridia of a leech, ventral view, h, testes; hb, urinary bladder; Ig, lateral blood-vessel; 71. ventral nerve cord; nh, epididymis; oi', ovary; p, penis; sc, nephridia; n, uterus and vagina; u(/, vas deferens: I'y, ventral blood-vessel. testes (//), the ducts of which unite to form a vas deferens on either side (ed). These pass forward, form by coiling a so-called epididymis (iiJi) and empty into the median unpaired penis (/)). In the space between the epididymis and the first p)air of testes are the ovaries (oi>) and oviducts and an unpaired vagina (?(â ). The nephridia (17 pairs in this species) are complicated and are pro- vided with bladder-like expansions. That the Hirudinei are true annelids and not segmentedPlathelminthes is based upon the view that their ccelom is reduced by ingrowth of paren- oliyma and altered to canals connected with the vascular system. At any rate the ventral and lateral vessels are to be regarded as remnants of a crulom. In Clepsi7ie there are the dorsal and ventral blood-vessels of tlie Chsetopoda and Vjesides four longitudinal crelomio sinuses connected by transverse anastomoses. The dorsal sinus encloses the dorsal blood- vessel, the ventral many of the viscera, among them the ventral nerve coi'd. This is also to be regarded as cailomio, since the nephrostomes con- nect with it. In most Hirudinei a canal system lilled with blood has arisen from thecoelom and blood-vessel, and in JS'epheHs is in part lacunar in character. Further relations arc shown by AcanthobdelJa j)e!ediiia, parasitic on lishes. This has both blood-vessels of the Oligochtetes, a. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colorati
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