Hygiene: a manual of personal and public health / by Arthur Newsholme.

  • Newsholme, Arthur, Sir, 1857-1943.
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: Hygiene: a manual of personal and public health / by Arthur Newsholme. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

    691/812
    perforating the skin. It burrows among the tissues, especially of the legs, and attains a length of several feet. The Filaria Sanguinis Hominis is a minute worm, about yV inch long, which infests the blood of man, chiefly in the tropics. Its mode of entry into the system is doubtful, hut it is probable that the ova of this worm may be introduced by mosquito bites, as well as by the drinking-water. Vast colonies of these worms circulate in the blood, and may produce various diseases* Com- monly, if a drop of blood is examined during the day, no filarise are detected, while at night they are present in abundance. It seems that they remain quiescent during the day, only migrating into the blood-vessels at night. The filarise sometimes accumulate in the lymphatic vessels and glands, and produce obstruction of the flow of lymph or chyle. In some cases, as a result, cliyluria (chyle in the urine) is produced; while in others Elejghantiasis^ characterised by enormous enlargement of the legs ‘and other parts, ensues. Tape-ioorms are found infesting the alimentary canal of man. Each has a double phase of existence. In the first, the character- istic head or scolex, along with a bladder-like body, lies imbedded in the solid tissues of an animal; in the second, the strohilus or tape worm, forming really a colony of animals, occupies the alimen- tary canal of another animal. The tape-worm consists of a number of flat segments, each of which is capable of producing eggs, from which a six-hooked embryo is developed. The segments escape from the alimentary canal, and their ova are discharged and scattered broadcast. These subsequently find their way into the alimentary canal of another animal, the hooked embryo escapes from its cell, migrates into the solid tissues, and there produces a scolex. The scolex remains in situ until its host perishes, or becomes the prey of another amimal. When the latter happens, the scolex enters the alimentary canal, loses its bladder-like body, and develops a chain of segments. It follows from the above that two, distinct hosts are usually necessary to complete the cycle of