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Show to the sponge domain. On the banks of the canal you may see growing plentifully plenti-fully in summer tinio a green sponge, which is the common fresh water species. spe-cies. Now if you drop a living specimen of this species into a bowl of water, and pnt some powdered indigo into the water, you may note how the currents are perpetually per-petually being swept in by the pores and out by the oscula. ITS NOUEISIMEXT. In living sponge this perpetual and unceasing circulation of water proceeds. This is the sole evidence the unassisted sight receives of the vitality of the sponge colony, and tho importance of this circulation cir-culation in aiding life in these depths to be fairly carried out cannot readily bo overestimated. ; Let us now see how this circulation is maintained. Microscopically regarded, we see here and there, in the sides of the sponge passages, little air chambers or recesa;s, which remind one of the passing pass-ing places in a narrow canal. Lining these chambers we see living sponge cnits of a type different from tho shapeless shape-less specks we noted to occur in the meshes of the sponge substance itself. The units of the recesses each consist of 3 linn" particle, whose free extremity is ra'sed into a kind of collar, from which projects a lashlike filament known as a flagellum. This lash is in constant movement. It waves to and fro m the water and the collection of lashes we see in any one chamber acts as a veritable veri-table brush, which by its movement not only sweeps water in the pores, but sends it onward through the sponge, and in due time sends it out by the bigger holes or oscula. : This constant circulation in the spongo discharges more than one important function. For, as already noted it serves the purpose of nutrition, m that the particles on which sponge life lssup-corted lssup-corted are swept into the colony. Again, the fresh currents of water carry with them the oxygen gas which is a necessity of sponge existence, as of human life; while, thirdly, waste matters, inevitably alike in sponge and in man as the result of living, are swept out of the colony and discharged into the sea beyond. Our bit of sponge has thus grown from a mere dry fragment into a living reality. It Is a community in which already, low bs it is, the work of life has come to be dischfr-ed by distinct and fairly special-S.aon special-S.aon Illustrated News, El : OF A SPONGE. jDevelopmeat from Articles of Pro-Si Pro-Si I toplasm How the Work of Hu- I trition is Carried On. w IMAETICLES PECULIARITIES piliar Scientific Talk With a Noted llTan The Sponge A3 An Adjunct it I to Civilization. first of all ve may note that a sponge, - Ie know it in common life, is the f x skeleton or framework which was p. I' by and which supported the liv- Iparts. These living parts consist of fate masses of that living jelly to I b the name of protoplasm has been M This, in truth, is the universal I'm of life. It is the one substance I I which life everywhere is associated, I as we see it simply in the sponge, so o I behold it (only in more complex I?) in the man. " low the living parts of this dried, raway sponge were found both in its trior and on its surface. They lined I canals that everywhere permeate the t 'ge like substance, and microscopic fiination has told us a great deal I their nature. For whether found lAe canals of the sponge themselves or l lded iu the sponge substance, the t-'S sponge particles aro represented lascmi-indcpendentmass of proto-So proto-So that the first view I would have f take of the sponge as a living mass is I ' it is a colony and not a single unit. Is composed, in other words, of aggre-11 aggre-11 masses of living particles which II out one from the other and manufac-P'he manufac-P'he supporting skeleton we know as t l-e sponge of commerce" itself. j I CNDER THE MICROSCOPE. j I lender the microscope these living I no6 nnits appear in various guises and I P. Some of them are formless, and, I to shape, ever altering masses, resem-PS resem-PS that familiar animalcule of our P we know as the amoeba. The fibers of the sponge colony form the f of the population. They are im-p im-p in the sponge substance; they f r about through the meshes of the f "JP: they seize food and flourish and J; andthey probably give origin to I We course produced, pure characteristic, however, are cer-P cer-P writs of this living sponge colony Pen livein the lining membrane of the IT8- In point of fact, a sponge is a P1 Venice, a certain proportion of P inhabitants, like the famous queen I he Adriatic herself, lived on the f of the waterways. Just as in puce ve find provisions for the dent Pfuf the city brought to the inhabi-f inhabi-f ts by the canals, so from the water, 1 5b, as we shall see, is perpetually cir- at,ig through a sponge, the members P-ponge colony receive their food. I"00 at a sponge fragment You per-l per-l re talf a dozen large holes or so, each pg on a little eminence, as it were, fc? aPrtures, bear in mind, we call ra- They are the exits of the sponge I -mon. But a close inspection of a Pge shows that it is riddled with finer t J smaller apertures. These latter are r" es, and they form the entrances |