. Common diseases of farm animals. Veterinary medicine. ANIMAL PARASITES 253 digestive juices free the larva, it then becomes attached to the intestinal mucous membrane and develops into the adult thorn- headed worm (Fig. 74). This parasite is characterized by a hooked proboscis or thorn at its anterior extremity, and the absence of a distinct digestive tract. The male is much smaller than the female. The eggs are passed out of the intestine with the Fig. 74.—Thorn-headed worms. The Round-worms or Nematoids,—Eound-worms are very common parasites of domestic animals (Fig. 75). This gro
. Common diseases of farm animals. Veterinary medicine. ANIMAL PARASITES 253 digestive juices free the larva, it then becomes attached to the intestinal mucous membrane and develops into the adult thorn- headed worm (Fig. 74). This parasite is characterized by a hooked proboscis or thorn at its anterior extremity, and the absence of a distinct digestive tract. The male is much smaller than the female. The eggs are passed out of the intestine with the Fig. 74.—Thorn-headed worms. The Round-worms or Nematoids,—Eound-worms are very common parasites of domestic animals (Fig. 75). This group of worms is characterized by their cylindrical form, the presence of a true digestive canal and the separation into two sexes, male and female. The life history is more simple than in the flat wonns. Intermediate hosts are not required for the develop- ment of the common forms. The eggs and embryos are deposited by the female in the intestinal tract, air passages, or excretory ducts of the kidneys of the host. Development may be com- pleted here, or the eo-gs and embryos are passed oif with the body excretions. They may live for a short time outside the animal. 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 Craig, Robert Alexander, 1872-. Philadelphia London, J. B. Lippincott company
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Keywords: ., bookpublisherphilad, booksubjectveterinarymedicine, bookyear1919
