. Annals of tropical medicine and parasitology. Parasites. 139 Water vasctdar system. A single ventral vessel runs along each lateral margin; that on the pore side lies ventral to the cirrus pouch and is situated further from the lateral margin than is the aporal vessel. This asymmetry is not, however, always pronounced. Internal Anatomy Male genitalia. Testes. The testes lie dorsal, and are about twelve in number; seven or eight lie on the aporal side of the ovary, one or two lie posterior and lateral to the yolk gland, and the rest— usually three—lie on the pore side of the ovary. They do no
. Annals of tropical medicine and parasitology. Parasites. 139 Water vasctdar system. A single ventral vessel runs along each lateral margin; that on the pore side lies ventral to the cirrus pouch and is situated further from the lateral margin than is the aporal vessel. This asymmetry is not, however, always pronounced. Internal Anatomy Male genitalia. Testes. The testes lie dorsal, and are about twelve in number; seven or eight lie on the aporal side of the ovary, one or two lie posterior and lateral to the yolk gland, and the rest— usually three—lie on the pore side of the ovary. They do not extend beyond the water vessels (figs. 3 and 4). t. Fig. 3. Davainea fiibrmanni, Segment showing male and female genitalia. —cirrus pouch; o.—ovary; —prostatic gland; —reccptaculum seminis; —sphincter muscle ; t—testes; v.—vagina; —vas deferens; —vaginal sinus; —ventral excretory vessel; —vitelline gland. X 140. Vas deferens. The vas deferens is a long, loosely coiled, slightly dilated tube, extending quite half way across the segment and surrounded throughout its length by a dense mass of glandular tissue—the prostate gland; it reaches its full development somewhat late. As no seminal vesicle was observed, it would appear that the elongated vas deferens functions as a seminal vesicle. The cirrus pouch is large, measuring in mature segments about 170/* long and 80/U broad : it lies across the antero-lateral angle of the segment and extends just internal to the lateral water vessel. The cirrus is armed with large spinules, measuring about 17/" ; these, however, cannot always be seen (figs. 3 and 4). Feviale genitalia. Ovary. The ovary is bi-lobed, each lobe having a rounded appearance. It lies slightly behind the centre of the segment (figs. 3 and 4).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and
Size: 2134px × 1170px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectparasites, bookyear19
