On the histology of Hydra fusca / by T. Jeffery Parker ; communicated by Professor Huxley.

  • Parker, T. Jeffery (Thomas Jeffery), 1850-1897.
Date:
1880
Catalogue details

Licence: Public Domain Mark

Credit: On the histology of Hydra fusca / by T. Jeffery Parker ; communicated by Professor Huxley. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    1/8
    t f-sy [From i/ie Proceedings of the Royal SocrE'^j No. ~r~r >Q,d880.] H: r 'biriii ]Q / “ On the Histology of Hydra fusca.” By, T. jEEEEj^r Parkek, B.Sc., Lecturer on Biology , in Bedford Collie, London, and Demonstrator in the RoyaLf^ghaOjl of'Jkimes. Commu- nicated by Professor Huxley, Sec. ITsT Received Decem- ber 11, 1870. (From the Biological Laboratory of the Royal School of Mines.) [Plate 1.] The few observations I have to offer on this much-discussed subject are partly confirmatory of, partly supplementary to, those of Kleinen- berg,* they present a certain agreement with those of P. E. Schulze,f while they are, in great measure, distinctly contradictory of the later researches of Korotneff. J 1. The Ectoderm and the Muscular Layer.—The layer of longitudinal fibres between the ectoderm and the endoderm was discovered by Kolliker, who believed that each fibre was in direct connexion with an endoderm cell. Kleinenberg, in teased specimens, saw that the ecto- derm cells tapered towards their inner ends, and that each was con- tinued into a simple or branched process, of precisely the same character as the fibres seen in sections : from this observation the important conclusion was arrived at, that the fibres were in direct continuity with the ectoderm cells, thus forming a sort of nascent mesoderm. Schulze figures the elements of the middle layer as fusiform fibres, with somewhat jagged edges. Korotneff, following Kleinenberg’s directions as to methods of preparation, came to the conclusion that the ectoderm cells were expanded (elargie) at their inner ends, and that each carried a fusiform refringent fibre, attached by its middle to the enlarged base of the cell, and projecting beyond it in either direc- tion, so that the cell appeared as a lateral appendage (annexe) of the fibre, rather than the fibre as a prolongation of the cell. How M. Korotneff can have come to this conclusion as to the shape of the ectoderm cells, it is rather difficult to imagine; by any ordinary method of preparation it is perfectly easy to satisfy oneself that the ectoderm cells of the body are, as a rule, markedly distinguished from those of the endoderm by the tapering of their inner ends; and, in good specimens, that these ends are continued into longer or shorter filaments. ■ The question of the exact relations of the fibres is by no means so easy to decide. Anyone working at Hydra for a week or two, * “ Hydra,” 1872. t “ Ueber den Bari u. die Entwicklung von Cordylopliora lucustris,” 1871. t “ Histologie de l’Hydre et de la Lucemaire.” “ Arch, de Zool. exp.,” t. v, (1«7G), p. 309.