constitute it, almost like so many rivulets or small streams that contribute to the maintenance of a large River. Nor from this _Hypothesis_ would it have been difficult to explicate, how those little branches of _Coral_, smal _Stones_, _shells_, and the like, come to be included by these frothy bodies: But this indeed was but a conjecture; and upon a more accurate enquiry into the form of it with the _Microscope_, it seems not to be the true origine of them; for whereas Sponges have onely three arms which join together at each knot, if they had been generated from bubbles they must have had four. But that they are Animal Substances, the _Chymical_ examination of them seems to manifest, they affording a volatil Salt and spirit, like _Harts-Horn_, as does also their great strength and toughness, and their smell when burn’d in the Fire or a Candle, which has a kind of fleshy sent, not much unlike to hair. And having since examin’d several Authors concerning them, among others; I find this account given by _Bellonius_, in the XI. _Chap._ of his 2d Book, _De Aquatilibus_. _Spongiæ recentes_, says he, _à siccis longe diversæ, scopulis aquæ marinæ ad duos vel tres cubitos, nonnunquam quatuor tantum digitos immersis, ut fungi arboribus adhærent, sordido quodam succo aut mucosa potius sanie ræfertæ, usque adeò fœtida, ut vel eminus nauseam excitet, continetur autem iis cavernis, quas inanes in siccis & lotis Spongiis cernimus: Putris pulmonis modo nigræ conspiciuntur, verùm quæ in sublimi aquæ nascuntur multo magis opaca nigredine suffusæ sunt. Vivere quidem Spongias adhærendo _Aristoteles_ censet: absolute vero minime: sensumque aliquem habere, vel eo argumento (inquit) credantur, quod difficillime abstrahantur, nisi clanculum agatur: Atq; ad avulsoris accessum ita contrahantur, ut eas evellere difficile sit, quod idem etiam faciunt quoties flatus tempestatésque urgent. Puto autem illis succum sordidum quem supra diximus carnis loco à natura attributum fuisse: atque meatibus latioribus tanquam intestinis aut interaneis uti. Cæterum pars ea quæ Spongiæ cautibus adhærent est tanquam folii petiolus, à quo veluti collum quoddam gracile incipit: quod deinde in latitudinem diffusum capitis globum facit. Recentibus nihil est fistulosum, hæsitantque tanquam radicibus. Superne omnes propemodum meatus concreti latent: inferne verò quaterni aut quini patent, per quos eas sugere existimamus_. From which Description, they seem to be a kind of Plant-Animal that adheres to a Rock, and these small _fibres_ or threads which we have described, seem to have been the Vessels which (’tis very probable) were very much bigger whil’st the _Interstitia_ were fill’d (as he affirms) with a mucous, pulpy or fleshy substance; but upon the drying were shrunk into the bigness they now appear.