. Cassell's natural history. Animals; Animal behavior. THE TRICHINA. 251 â by the muscular fibres or glands. Tlie cliitinous tube of the pharynx may have longitudinal projections called teeth, but the office of the gullet is that of a sucker or tube. In some Nematoidea the intestinal canal, in part or wholly, undergoes retrogressive development during the parasitism. The skin, more or less tough, and often striated across, is formed of several layers partly composed of fibres, and rests on a soft, finely granular tissue with nuclei. Beneath this is a musculo- cutaneous envelope with flat and f
. Cassell's natural history. Animals; Animal behavior. THE TRICHINA. 251 â by the muscular fibres or glands. Tlie cliitinous tube of the pharynx may have longitudinal projections called teeth, but the office of the gullet is that of a sucker or tube. In some Nematoidea the intestinal canal, in part or wholly, undergoes retrogressive development during the parasitism. The skin, more or less tough, and often striated across, is formed of several layers partly composed of fibres, and rests on a soft, finely granular tissue with nuclei. Beneath this is a musculo- cutaneous envelope with flat and fusiform muscular fibres. The surface of the skin may be ixtestixal of a nematoid. (.After Gojenhm covered with ridges, tubercles, spines, or hair, and moulting takes place in the young. Some Nematoidea have eye-spots, at the end of the body, with or without refracting bodies in them. Most have the sexes separate, and usually the males are smaller than the females. Of late years much attention has been paid to a very remarkable Nematoid parasite which has been called Trichina spiralis by Owen. Gritty particles were found in human muscles, by the late Mr. Hilton, , of Guy's Hospital, who recognised them as the results of parasites. Sir James Paget, when a student, first determined the existence of the minute worms which produce the gritty parts; and Robert Brown, the botanist, assisted, by lending his microscope to the now distinguished surgeon. In the year following. Professor Owen described the worm scientifically, from â¢specimens sent him by Mr. Worniald, Paget's colleague. Leuckart discovered the history of the parasite, tracing it to its source and method of propagation ; and Zenker explained the symptoms of infected men, and detected the young in the act of migration. The worm was named from its very commonly being seen in a capsule, rolled up in a spiral shape. When mature and able to reproduce its kind, and therefore fully developed. Trichina sjnralis is
Size: 1386px × 1803px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjecta, booksubjectanimals
