The natural history of the British Entomostraca / By W. Baird.

  • Baird, William, 1803-1872.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: The natural history of the British Entomostraca / By W. Baird. Source: Wellcome Collection.

    18/456 (page 6)
    Then, when life had fairly ceased, they rioted upon their flesh, and in a few hours little but the external covering was left. I have no doubt that most of the Entomostraca are essentially carnivorous, and [ have frequently seen speci- mens of Cypris in their turn, as soon as dead, attacked immediately by quantities of the Cyclops quadricorais, who in a few minutes had fastened themselves upon the dead animal, and were so intent upon their prey, that they were scarcely frightened away from it by bemg touched with the brush. In a short time the Cypris might be seen lymg at the bottom of the vessel, the valves of the shell separated and emptied of their contents. Leeuwenhoek and De Geer not only maintain that the Cyclops quadri- its own young, a fact which I have also noticed myself. Jurine asserts that the Cyclops quadricornis is carnivorous from taste, and only herbivorous from necessity ; while the Daphnia pulex, he distinctly affirms, lives upon ani- malcules. Place a few Entomostraca, such, for example, as the Daphnize, Chirocephali, Lyncei, &c., in a vessel with * clear pure water, and only some vegetable matters in it, and they gradually become languid, transparent, and finally die; but mix with this water some which contains nu- merous Infusoria, and the Entomostraca will then be seen speedily to assume another aspect. ‘They become lively and active, and the opacity of their alimentary canal testifies sufficiently the cause of it. When, indeed, we consider the amazing quantity of animals which swarm in our ponds and ditches, and the deterioration of the surrounding — atmosphere which might ensue from the putrefaction of their dead bodies, we see a decided fitness in these Ento- mostraca being carnivorous, thus helpmg to prevent the noxious effects of putrid air which might otherwise ensue ;_ - whilst they in their turn become a prey to other animals, _ which no doubt serve their purposes also in the economy * of nature. The fresh-water Gammari seem to prey upon them, and the Hydrachne are their decided enemies ;