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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    drical or spindle-shaped form, with the head greatly rounded; the tail is short, conical, and somewhat pointed. Proboscis longer than the body in its extended condition. When young, they are green, but when full grown, are of a blood-red colour. The motion of this variform ani¬ malcule is generally slow, and it sometimes revolves upon its longitudinal axis in swimming. Its colour is not of a fixed character, some being green, others spotted red and green—a mixture of both. This arises, according to Ehren- berg, from the different condition of the ova at different times, and which cover numerous granular round bodies, supposed to be digestive cells. The thread-like proboscis, which is a prolongation of the upj^er lip, and rather longer than the body, is so delicate, as to require considerable care in investigating it, and being retractile, will often elude our observation. A little colouring matter in the water will exhibit this organ in active operation, and it may be distinctly seen in a single animalcule, in a dried state, upon a plate of clear glass. The double appearance of the organ in this species has been before noticed. Ebrenberg conjectures that the miracle in Egypt, recorded by the great lawgiver of the Jews, of turning the water into blood, might have been effected by the agency of these creatures, or by the Astasia hjematodes. Figures 7l> 72, and 73, represent the creature in different states. In the first, it appears elongated, and currents in the water are shewn near the mouth. In the others, the cilia-formed thread-like proboscis is seen. Found in stagnant water ; often in great abundance on the surface of ponds. Length 1-300th to 1-240th., 127. Eugeena hyalinu. The crystal-like Euglena.—