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

John Hogg

Date:: [1841]

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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$*') v> / ■J V . -i/v l\.~Remarks on the Horny Sponges, with proposed the Order Spongiae. By John Hogg, liisq., ^ F.L.S., &c. To the Editors of the Annals and Magazine of Natural Gentlemen, Mr. Bowebbank having published some very interesting ^ Observations on a Horny Sponge from Australia,^ at p. 129 of the ‘Ann. and Mag. of Nat. Hist.^ for April 1841, I am induced to trouble you with a few remarks upon them. The author there writes, “ that, contrm’y to received opi- nions, they^’ (horny sponges) “ are furnished with siliceous spicula.” This opinion, however, which seems to me to have originated from Dr. Grant^s examinations of some of oui Bii- tish horny sponges, and from the statement which he has made in the ‘Edinburgh New PhilosophicalJournaP (forl827, p. 122), where he says—“I have never observed any kind of spiculum in the horny species,^^ is incorrect as far as it relates to cdl the horny, or subcorneous, sponges. Because, by re- ferring to M. Lamarck’s ‘Hist. Nat. des Anim. sans Verteb.,’ tom. ii., edit. 1836, p. 538, it will be seen that M. Milne Edwards distinctly mentions some sponges which were de- scribed by M. Savigny and figured in the plates of his superb work on Egypt, as having “la disposition du reseau come et des spicules qui constituent en quelque sorte la charpente de ces corps.” Now, since M. Milne Edwards has in the preceding page (537) expressly said that “ on ne commit pas d’especes qui en presentent conjointement avec des epines calcaires et des fibres cornees,” it is quite certain that the “ reseau come et des spicules” spoken of, and which were described by M. Savigny, must signify the skeleton of a horny net-ivork with siliceous spicula. Thus Mr. Bowerbank, by his late investi- gations, has fortunately confirmed this fact; and has disco- vered the presence of siliceous spicula in some other species of the horny sponges, which species were previously sup- posed to be entirely destitute of them. But as it was like- wise generally thought that the siliceous spicula seldom or never put on more than two simple forms, it is of importance to find from that author’s paper that he has proved the sili- ceous spicula in the horny sponges which he examined to exist under several difevent forms, some of which he has re- presented in the accompanying figures, (Plate III. Vol. vii.) The next objects worth especial notice in that paper are, first, the reticulations of the transparent membrane. These, B 2$

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

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