Remarks on the horny sponges, with proposed divisions of the order Spongiae / by John Hogg.

  • John Hogg
Date:
[1841]
Catalogue details

Licence: Public Domain Mark

Credit: Remarks on the horny sponges, with proposed divisions of the order Spongiae / by John Hogg. 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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    indeed, strongly resemble those of the membrane of the Spon- gilla fluviatilis, which I have described at p.386 of the ‘Lin- naean Transactions,’ vol. xviii., and the second, the fixed spo- ridia ;—the actual existence of these bodies in any of our Bri- tish sea sponges I have never yet been able to witness, and which I account for from my not having examined them in their native localities at the proper season of the year. Al- though previously figured in Donati’s work and in the ‘ Zoo- logia Danica,’ the fixed sporidia were first distinctly pointed out by Dr. Ehrenberg, as having been seen by him in many sponges of the Red Sea. The reticulated transparent membrane and the fixed spo- ridia, then, fully confirm the general description of the Spongice Marinos which I gave at p. 400, ‘ Linn. Trans.,’ vol. xviii., in these words :—“ The sea sponges are furnished with a skeleton of fibres interlacing, crossing, and anastomosing with them- selves ; generally also strengthened with those singularly crystallized particles termed spicula; with a parenchymatous soft portion or jelly; with a fine and transparent enveloping membrane; with numerous minute pores; and frequently with larger orifices or oscules, which are more sparingly and irregularly dispersed over their sui’faces; with passages or canals communicating through the pores and oscules one with another, along which the water finds a ready course or circu- lation, and affords nutriment to all the inner parts of the masses; with locomotive sporules ; and in some species with fixed sporidia.” Mr. Bowerbank has however omitted to say whether these sporidia were softish or hard, and whether the parenchyma- tous portion or jelly was composed of minute globules or not; nor has that author given us the names of the species which he has described. Next, if we examine Mr. Bowerbank’s plate, we see the fixed sporidia well drawn at fig. 8 in their natural position, but he has neglected to magnify any of them separately. Fig. 7 gives a representation oif the reticulated transparent membrane, which, I believe, is quite new, and has never yet been figured in any engraving of the sponges. Again, Mr. Bowerbank in the abstract of his paper, which was communicated to the Microscopic Society, and published in No. 1 (for March last) of the ‘ Microscopic Journal,’ men- tions some of the horny sponges of commerce that were re- ceived from the Mediterranean, in which spicula were like- wise discovered; but the vascular tissue surrounding the fibres there described, I am strongly inclined to agree with Dr. George Johnston in thinking “as of no more than specific importance.”
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