Parasites : a treatise on the entozoa of man and animals including some account of the ectozoa / by T. Spencer Cobbold.

  • Cobbold, T. Spencer (Thomas Spencer), 1828-1886.
Date:
1879
Catalogue details

Licence: Public Domain Mark

Credit: Parasites : a treatise on the entozoa of man and animals including some account of the ectozoa / by T. Spencer Cobbold. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    Strongylida, Trichinidce, Oxijuridai, Tricliocephalidce, Filarida, Gordiidce, Angxdllulidce, IV. Thornhea-dbd-worms. Acanthocephala—This group embraces a small series of parasites, which, in general appear- ance, resemble the nematode worms. They differ, however, essentially, being, as the term indicates, furnished with spine- covered heads. They are, moreover, destitute of digestive organs. The species are entozoal in habit, abounding particu- larly in fishes and reptiles. At present, all the known forms are included in one family {Echinorhynchidce), which also comprises only a single genus. V. Annelid parasites. Suctoria.—In this category one must place all such suctorial annelids as affix themselves to hosts for a longer or shorter period. Many of the leech- like parasites {Glepsinida, and especially Mallacohdellida) remind one of certain flukes {Tristoma, &c.) possessing ectozoal habits; whilst the leeches, properly so called, afford instances of the passage from a semi-parasitic to what has been called the free parasitic mode of existence. In tropical countries these creatures very readily attach themselves to man and animals, often creating severe distress. The genera Glepsine and Ecemocharis attack mollusks and fishes respectively. The species are all ectoparasitic and exceedingly numerous. They cannot be described in this woi'k. YI. Arachnid parasites. Arachnida (part of).—The great class of articulated, limb-jointed, or, more strictly, arthro- podous animals, includes a variety of parasites. The mites, true ticks, and such like creatures, belong to this group. Some few of them are entozoal in habit, others are only par- tially so, whilst the majority are entirely ectozoal. Of the two great sections of Arachnida, namely, Pulmonaria and Tra- chearia, the latter alone contains strictly parasitic forms. The parasitic species belong to the following families :—Pentasto- midce, Pycnogonidce, Ixodidce, Acaridce, Gamasidce, Hydrach- nida, Solpugidce. The parasitism of some of the species is very partial or slight. Thus, certain of the water mites, in their juvenile state, dwell on aquatic insects only; and the tick-like Gamasidae occur upon dung-beetles. The other ectozoal species attack vertebrated animals, and several attach themselves to man himself. The whale lice [Gyamidce] are here included in the Pycnogonida-, though often placed by zoologists with the Crustaceans.