Comparative anatomy / by C.Th. v. Siebold and H. Stannius ; translated from the German, and edited with notes and additions recording the recent progress of the science by Waldo I. Burnett.

  • Karl Theodor Ernst von Siebold
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Comparative anatomy / by C.Th. v. Siebold and H. Stannius ; translated from the German, and edited with notes and additions recording the recent progress of the science by Waldo I. Burnett. 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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    often be seen the so-called organization of Ehrenberg's Monadina and Volvocina. Until the fact that ciliated organs belong to both animals and vegetables was decided, the real place of many low organisms had to remain undetermined.<4) However, notwithstanding their free motion from place to place by means of cilia, the vegetable nature of many organisms seemed clearly indicated by the rigid, non-contractile character of their forms. It is from a misapprehension of the true nature of these facts, that some modern naturalists have denied the existence of limits between the two kingdoms.® With Bacillarese and Diatomaceae, this question has another aspect. Many of these organisms have been taken for animals from their so-called voluntary movements, which truly entirely want the character of volition. In the movements of the rigid Diatomaceas, for instance, the whole plant has oscillatory motions like a magnetic needle, at the same time slightly changing its place forward and backward. When small floating particles come in contact with such an organism, they immediately assume the same motion. This may be well observed with the Oscillatoria. There are here, undoubtedly, no ciliary organs ; in fact, they could not, if pres- ent, produce this kind of motion. According to Ehrenberg,^ the iNaviculae can protrude ciliary locomotive organs through openings of their carapace; but this has not been observed by other naturalists. §4- The Rhizopoda, whose internal structure is as yet imperfectly known, are closely allied to the Infusoria. Like these last, their bodies are cellu- lar, containing nuclear corpuscles, but no system of distinct organs. These two classes of Protozoa differ, however, in their external form, and the structure of their locomotive organs. The body of the Infusoria, notwith- standing its contractility, has a definite form, and moves chiefly by means of vibratile organs. That of the llhizopoda, on the other hand, although equally contractile, has no definite form; their movements also are not due to ciliated organs, but to a change of the form of the body by various prolongations and digitations. § 5. Owing to the present incomplete details upon the organization of these animals, little can here be said about them ; and therefore, instead of devoting to them a separate chapter, it will be proper to treat of them with the Infusoria in general. As the division of the Polygastric Infusoria, by Ehrenberg, into two 4 As an example, may be mentioned the various and dissimilar opinions of naturalists upon the question of the animal or vegetable nature of the “red snow j ” a question upon which FLntow, after the most careful studies, is still undecided. See Flotow, “ Ueber Ilaematococcus pluvialis, ” in Nov. Act. Acad. Leop. Carol, vol. XX. part ii. p. 18. 6 See Unger, Die Pflanze im Momente der Thierwerdung. Wien. 1843. Also, Kiitzing, Ueber die Verwandlung der Infusorien in niedere Algenformen. Nordhausen, 184-1. In an academic paper (Dissertatio de finibus inter regnum animate et vegetabile constiluendis, Erlangae, 1844), I have attempted to show that this confusion between the two kingdoms does not exist. o Abhandlungen der Akademie der Wissen- schaften zu Berlin, 1836, p. 134, Taf. I. tig. 19, and 1839, p. 102, Taf. IV. iig. 5.