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

  • Thomas Jeffery Parker
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.

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    For sections showing the cilia of the endoderm, the Hydros were kept for twenty-four hours in 1 per cent, osmic acid, then washed, and preserved in weak glycerine until required for cutting. The sections were cut by Dr. Pritchard’s very convenient freezing micro- tome, the specimens being placed in gum water before freezing. DESCRIPTION OF PLATE. Reference letters. en., endoderm. f, food particles. d., diatom included in an cell. c., cilia. endoderm ec., ectoderm. m., middlo layer. in. p., muscular processes. s. 1., supporting lamella. i. t., interstitial tissue. ne., nematocysts. Figure 1. Longitudinal section of the body, distal end, (ammonic bichromate— alcohol—eosin). The specimen was killed in full digestion, the endoderm cells being gorged with food particles, amongst which is a diatom frustule. The ectoderm and endoderm are unnaturally separated by the action of the bichromate, and the supporting lamella is not shown. The nuclei are not well shown, the specimen having been unfortunately stained with eosin instead of carmine. Figure 2. Fragment of the supporting lamella, obtained by teasing, (osmic acid— weak glycerine). The wavy character of many of the adhering muscular processes is well seen. Figure 3. Longitudinal section of the body, distal end, (osmic acid—weak glycerine), showing particularly the flagella of the endoderm cells. The boundaries of the ectoderm cells are not seen. Figure 4. Transverse section of the body, proximal end, (picric acid—alcohol— carmine), showing the pseudopodia of the endoderm cells and the included food particles, as also the absence of interstitial tissue and of nematocysts in this region. Figure 5. Longitudinal section of a tentacle, (picric acid—alcohol—carmine). In this section, selected as showing the food particles in the protoplasm of the endoderm cells, no nematocysts, nor palpocils are to be seen. Figure 6. Longitudinal section of the body, distal end, to show the typical structure of the body wall. Figures 1—5 are accurately drawn, each from a single specimen, except for the fact that the diatom d, in fig. 1, has been inserted from a similar, but otherwise less favourable specimen. Fig. 6 is a combination of several preparations, being the correct proportions retained. All the figures were drawn with a G-undlach’s -J(Tth immersion (for the use of which I am indebted to Professor Huxley) on Hartnack’s small stand, and with his No. 3 eye-piece. HARRISON AND SONS, TRINTERS IN ORDINARY TO HER MAJESTY, ST. MARTIN’S LANE.
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