. A text-book of agricultural zoology. Zoology, Agricultural; Zoology, Economic. 60 NEMATODE WORMS. moults precede the adult stage. The simplest form of develop- ment is where the embryo, enveloped still in its egg-membrane, is transported, passively, in the food to the host (Oxyuris). In the Ascaridm the embryo, which is provided with a boring tooth, may pass sometimes into an intermediate host, by which it is transported with its host in food and water into the second host, where it will become sexually mature. The food of Nematodes which are parasitic consists of the organic juices of the b
. A text-book of agricultural zoology. Zoology, Agricultural; Zoology, Economic. 60 NEMATODE WORMS. moults precede the adult stage. The simplest form of develop- ment is where the embryo, enveloped still in its egg-membrane, is transported, passively, in the food to the host (Oxyuris). In the Ascaridm the embryo, which is provided with a boring tooth, may pass sometimes into an intermediate host, by which it is transported with its host in food and water into the second host, where it will become sexually mature. The food of Nematodes which are parasitic consists of the organic juices of the body. They nearly all seem to lead a free life during some period of their existence. Tho.^e that are. Fig, 18.—Anguillulid^ (Eelworms). Li, Mature 9 with oral spine ; & and c, ova ; d, extremity' of £ ; e, anterior of adult. (Enlarged, after Ritsema Bos.) parasitic in plants, causing such diseases as clover-sickness, ear- cocldes or purples in corn, &c., are called eelworms. Many of these eelworms, however, only live in decaying parts of plants, where they do no harm : these are termed saj^hrophytes. Yet others produce fermentations, such as tlie Vinegar- and Paste- Eelworms. In all cases both egg and cyst of these Nematodes have the power to resist extreme heat and cold, unless it be that the former is kept up for some 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
