. A text-book of agricultural zoology. Zoology, Agricultural; Zoology, Economic. 48 VARIOUS FORMS OF TAPEWOKMS. to the intestine. There is no yet, however, that the fox does harbour this worm. It can be distinguished by having a circle of hooks around its head, which is sliglitly drav/n out into a rostellum, and by its four suckers. In length it varies from twelve to sixteen inches when adult, and is constituted of about two hundred distinct segments. The pale proglottides full of eggs are passed out on to the ground in the sheep-dog's excre- ment, and there remaining for a short period
. A text-book of agricultural zoology. Zoology, Agricultural; Zoology, Economic. 48 VARIOUS FORMS OF TAPEWOKMS. to the intestine. There is no yet, however, that the fox does harbour this worm. It can be distinguished by having a circle of hooks around its head, which is sliglitly drav/n out into a rostellum, and by its four suckers. In length it varies from twelve to sixteen inches when adult, and is constituted of about two hundred distinct segments. The pale proglottides full of eggs are passed out on to the ground in the sheep-dog's excre- ment, and there remaining for a short period, they burst, re- leasing thousands of ova (a). These are taken off the grass hy. Fig. 12.—Sturdy in Sheep (Ccvmirus cerebndis anil Ta'/iut canurus). A, Ovum. E, Embryo, o, Sexual worm (Ta'^m cffirij/j-w.^):;., proglottides ; », neck; s, suckers. r>, ,^ cercbrali^: c, cerebral hemispheres; cb, cerebellum: m, medulla, e, Hoolc from o. the lambs, or even two-year-old sheep ; sometimes even whole segments may be devoured. In either case the embryos become released in the stomach of the sheep. The sis-hooked larvje then commence to bore their way through the walls of the ovine intestine, and finally enter the blood, by which they are carried to various parts of the body. Should any of these embryos reach the brain or spinal cord, as very often happens, further development takes place ; otherwise thoy apparently die a pre- mature death. After the larva has reached the cranium, it com-. 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 Theobald, Frederick Vincent, 1868-1930. Edinburgh and London, W. Blackwood and Sons
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1899
