A history of infusoria, living and fossil: arranged according to "Die Infusionsthierchen" of C.G. Ehrenberg. Containing coloured engravings, illustrative of all the genera, and descriptions of all the species in that work, with several new ones. To which is appended an account of those recently discovered in the chalk formations / By Andrew Pritchard.

  • Pritchard, Andrew, 1804-1882.
Date:
1841
Catalogue details

Licence: Public Domain Mark

Credit: A history of infusoria, living and fossil: arranged according to "Die Infusionsthierchen" of C.G. Ehrenberg. Containing coloured engravings, illustrative of all the genera, and descriptions of all the species in that work, with several new ones. To which is appended an account of those recently discovered in the chalk formations / By Andrew Pritchard. Source: Wellcome Collection.

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    tracts also upon the action of certain re-agents, whose effects cannot be considered purely chemical. 3rdly. The comparison of the supposed ova with the cytoblasts and cells of plants precludes the possibility of our considering them as the latter, while the appearance of a vitelline nucleus, transparent but molecular fluid, a chorion or shell, determines them as animal ova. It was shown to be impossible that these eggs had been deposited in the empty shell by other infusoria, or that they were the produce of some entozoon. “ 4thly. That while it was impossible to determine whether the vague motions of Closterium were voluntary or not, yet the idea the author had formed of a suctorial apparatus forbad his classing them with plants. “ Lastly, in no instance had the action of iodine pro¬ duced its ordinary effects upon starch or vegetable matter, by colouring it violet or blue, although Meyen asserts it did in his trials.” The author therefore concluded that Closterium must still be retained as an infusory animal, although it is more than doubtful whether it ought to rank with the polygastric families. Genus XXXI. Closterium. The spindle Animalcules.— This genus comprehends all the known members of the family; the characteristic features of the latter, therefore, answer for the genus. Twenty-seven species have been described, although but sixteen are clearly determined. 104. Closterium lunula {Vibrio lunula, M.) The half-moon-shaped Closterium.—Lorica smooth, crescent¬ shaped or straight, attenuated and rounded at the apices. Glandular substances scattered over the interior of the