A practical guide to meat inspection (Walley) / re-written and enlarged by Stewart Stockman.

Date:
1901
Catalogue details

Licence: In copyright

Credit: A practical guide to meat inspection (Walley) / re-written and enlarged by Stewart Stockman. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    c Fig. 77. — Pupa of Linguatula tsenioides nine weeks old.— Leuckart, Neumann. intestines. Theseembryos measure 130 ^ x GO Theyresemble acari in shape. The dorsal surface is convex and the ventral is flat. They have two pairs of legs, each of which ends in two claws. At their anterior part they are armed with a boring apparatus shaped like a spur. The embryos bore their way into the abdominal and thoracic organs, where they be- come encysted. I11 the cysts they lose their legs and boring apparatus, and become trans- formed into pupae, measuring *3 mm. x T8 mm. During the next six months the larva undergoes several changes, which result in the form termed Linguatula denticulata. In this form it measures from 6 to 8 mm. It is shaped like an almond. The body is denticulated at its margins, and is made up of from 80 to 90 rings. It has hooks on its anterior end. The digestive tube runs the whole length of the body. The genital organs are rudimentary (Fig. 78). Lesions.— The embryos penetrate to the mesenteric glands, the liver, the lungs, and less frequently to the kidneys. At first there is little alteration in the organs, but the invaded ones become hollowed out by small cavities as the parasites develop. The neighbouring cavities become confluent, and form larger cysts. I11 this way a gland may undergo atrophy, and be converted into a small cvst containing nothing but a brownish %j o o fluid and larvae. At first the invaded glands show to the naked eye only a few brownish coloured spots. They ultimately become fibrous, and may show tubercle-like areas. Manv of the denticulata perforate the walls of the cysts and gain the peritoneal cavity. According to Leuckart, they may again pierce the other abdominal organs or migrate to the lungs (Fig. 79). The animals whose mesenteric glands are extensively in-