An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium; r, rectum; and Br, Ctenidia.

Chiton Excretory and Reproductive Organs

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium;…

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium; r, rectum; Cl, Cloacal or pallial chamber of Neomaniae and Chaetoerma; and Br, Ctenidia.

Chiton Excretory and Reproductive Organs

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium;…

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium; r, rectum; and Cl, Cloacal or pallial chamber of Neomaniae and Chaetoerma.

Chiton Excretory and Reproductive Organs

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium;…

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium; r, rectum; and Cl, Cloacal or pallial chamber of Neomaniae and Chaetoerma; Br, Ctenidia; g, External aperture of the gential duct of Chiton; and u, External aperture of nephridium.

Chiton Excretory and Reproductive Organs

An illustration of a chiton's excretory and reproductive organs. O, Ovary; P, Pericardium; N, Nephridium;…

"Development of excretory system of vertebrate. The primitive segments are not separated off from the lateral plate, and the pronephros (pn.) is seen arising from the lower part of the primitive segment.n.c., nerve cord; nch., notochord; pn., pronephros; g., gut; p.s., primitive segment; mes., mesonephric tubule; pn.d., pronephric duct; b.c., body cavity; ao., aorta; siv., sub-intestinal vein, with vessel to the aorta." -Thomson, 1916

Excretory System Stage 1

"Development of excretory system of vertebrate. The primitive segments are not separated off from the…

"Development of excretory system of vertebrate. The pronephros is completely separated off from the primitive segment and lateral plate.n.c., nerve cord; nch., notochord; pn., pronephros; g., gut; p.s., primitive segment; mes., mesonephric tubule; pn.d., pronephric duct; b.c., body cavity; ao., aorta; siv., sub-intestinal vein, with vessel to the aorta." -Thomson, 1916

Excretory System Stage 2

"Development of excretory system of vertebrate. The pronephros is completely separated off from the…

"The origin of the mesonephric tubules is seen. They arise from the upper part of the lateral plate, which is now completely separated from the primitive segment, and curving round the pronephric duct come to open into it.n.c., nerve cord; nch., notochord; pn., pronephros; g., gut; p.s., primitive segment; mes., mesonephric tubule; pn.d., pronephric duct; b.c., body cavity; ao., aorta; siv., sub-intestinal vein, with vessel to the aorta." -Thomson, 1916

Excretory System Stage 3

"The origin of the mesonephric tubules is seen. They arise from the upper part of the lateral plate,…

This is a diagram of transverse section of a Turbellarian through the region of the mouth. d.m., dermo-muscular wall containing longitudinal fibres; ex, excretory system; f, flame cells; g, gut; l.c., lateral nerve cord; m, mouth; m.f., muscle fibres; ph., pharynx; t, testis; u, uterus; y, yolk glands.

Turbellarian

This is a diagram of transverse section of a Turbellarian through the region of the mouth. d.m., dermo-muscular…