. A manual of elementary zoology . Zoology. ANNELIDA : THE LEECH 237 than the rest and extends backwards on each side of the remainder of the alimentary canal. This consists of the stomach—a narrow tube, with an enlargement at its start and a spiral fold of its inner wall—the intestine, narrower than the stomach, and the rectum, somewhat wider. The blood sucked for food is stored in the crop, whose caeca are more or less dilated according to the amount of their contents, and passed drop by drop into the stomach, d-S- Fig. 152.—A transverse section of the medicinal leech. —After Bourne. b.
. A manual of elementary zoology . Zoology. ANNELIDA : THE LEECH 237 than the rest and extends backwards on each side of the remainder of the alimentary canal. This consists of the stomach—a narrow tube, with an enlargement at its start and a spiral fold of its inner wall—the intestine, narrower than the stomach, and the rectum, somewhat wider. The blood sucked for food is stored in the crop, whose caeca are more or less dilated according to the amount of their contents, and passed drop by drop into the stomach, d-S- Fig. 152.—A transverse section of the medicinal leech. —After Bourne. , Botryoidal tissue; cm., circular muscles; cap., capillary; cr., crop; ci*'., a csecum of the same; CM., cuticle; dm., dorsoventral muscle; , dorsal sinus; ej>., epidermis ; , gland cells ; /.«., longitudinal muscles ; Lv., lateral vessel; nerve cord ; testis ; , testis sinuSj with end of nephridium ; , vas deferens. where it at once turns green and then is digested. A full meal will last the animal for several months or a year. Seventeen pairs of nephridia lie in segments 7-23. Each is a mass of glandular tissue traversed by a system of intracellular ductules. There is no internal opening, but those which lie in the testis segments have a swollen end lying in the capsule of the testis, and bearing a number of ciliated funnels which do not communicate with the ductules. There are two systems of tubes which contain a fluid like blood—a red plasma with a few colourless. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Borradaile, L. A. (Lancelot Alexander), 1872-1945. London : H. Frowde, Hodder & Stoughton
Size: 1955px × 1278px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1920
