Abstract
THE current number of the Quarterly Journal of Microscopical, Science commences with an account by Mr. Wm. Archer of a new freshwater sarcodic organism, named by the author Chlamydomyxa labyrinthuloides, which is illustrated by a superb foliosized coloured plate, as well as an octavo one. The species is shown to be closely allied to Labyrinthula of Cienkowski. The matrix is enclosed in a multilaminate cellulose envelope, which at times appears to burst and give exit to protoplasmic contents, which emerge in an arborescent manner with hyaline prolongations, along which small fusiform protoplasmic masses travel.—Rev. M. J. Berkeley gives a short account of the Thread Blight of Tea, in which he describes the fungus producing it, although he is unable to name it because he has not had an opportunity of examining the fructification.—Mr. P. Kidd draws attention to the occurrence of spontaneous movement in the nucleoli of the epithelium of the frog's mouth.—This paper is followed by an excellent and illustrated account of the structure of the Pacinian corpuscles, considered with reference to the homologies of the several parts composing them, by Mr. Edward Schäfer, in which it is shown—assuming an ordinary nerve fibre to consist of the axis cylinder in the middle, surrounded by, first, the medullary sheath, or white substance; secondly, a delicate layer of protoplasm containing nuclei; thirdly, the primitive sheath (of Schwann); and lastly, the numerous laminæ of the neurilemma, which, however, encloses a layer of finely filamentous connective tissue—that the coats of the Pacinian are the layers of the neurilemma; that the sheath of Schwann surrounds the core, this latter being an expansion of the protoplasmic substance; that the medullary sheath, if not retained as such, disappears, and that the axis-cylinder becomes the central fibre.—Mr. A. W. Bennett gives an account of modern researches into the nature of yeast, specially noticing those of Reess and Cienkowski.—Prof. Lankester has a paper of special theoretical importance, on the Invaginate Planula, or Diplobastic Phase of Paludina vivipara; in which, after proposing the name “blastopore” for the orifice of invagination of those Planulæ which exhibit it, he proposes a a classification of Planulæ, which helps to simplify this intricate part of embryonic history. He divides Planulæ into two groups: Delaminate Planulæ, in which there is no invagination, but a splitting of the blastosphere to form the endo- and ecto-derm; and Invaginate Planulæ, which may be embolic, or have no food-yelk; or epibolic, possessing a “residual yelk.” The Hydrozoa and Calcareous Sponges have delaminate planulæ; Amphioxus, Ascidians, many Mollusca, Sagitta, Echinodermata, and many Vermes have embolic invaginate planulæ; whilst in the third group are included many Mollusca, many Vertebrata, the Ctenophora, certain Vermes, and certain Arthropods.—Mr. H. C. Sorby describes the absorption spectrum of Bonellia viridis, and draws attention to a most striking point, namely, that there seems to be a constant ratio between the wave-lengths of the different bands in these spectra.—The number contains its usual excellent quarterly chronicle, notes, & c.
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Scientific Serials . Nature 12, 16–17 (1875). https://doi.org/10.1038/012016b0
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DOI: https://doi.org/10.1038/012016b0