118 THE SEA. 



miles of sea. They constitute one of the principal supports of the whale. They are themselves 

 singularly voracious, and snap up their prey small molluscs, young crustaceans, and annilids 

 at a mouthful. Their mouths are in the centre of the lower side of the umbrella. They vary 

 from a very small size to as much as a yard in diameter, while to describe the known varieties 

 would occupy the remainder of this volume, so numerous are they. It has been ascertained 

 that these jelly-like creatures breathe through the skin, have a distinct circulation and some 

 nervous sensations. Most of them produce a stinging pain when they touch the human body, 

 and until lately they were, adopting Cuvier's classification, designated Acalep/ttf, or "sea- 

 nettles," in consequence. 



Nearly all the other Hydrozoa are marine productions, and comprise among them numerous 

 beautiful forms. Take, for example, the polyp known as Praya diphyes, a double, bell-shaped 

 body, with a long tail, as it were, of feelers, a floating fishing-line ; or, another delicate 

 organisation of the same family, Galcolaria anrantiaca, the orange galeolaria. Here are 

 two floating bladders with a connecting chain of polyps ; the floats aiding to support, as it 

 were, a whole colony ! But the large order PJtytopkorida deserves more than a mere passing 

 notice, on account of the graceful forms of delicate tissue and colour which are included, 

 under it. 



These inhabitants of the sea are essentially swimmers, having mostly true swimming 

 bladders, more or less numerous and of varied form ; they always float on the surface. 

 M. de Quatrefages, the distinguished French naturalist, describing one of these 

 organisms, Apolemia contorta, tells the reader "to figure to himself an axis of flexible 

 crystals, sometimes more than a metre (forty inches) in length, all round which are 

 attached, by means of long peduncles or footstalks equally transparent, some hundreds 

 of bodies, sometimes elongated, sometimes flat, and formed like the bud of a flower. If 

 we add to this garland of pearls of a vivid red colour and infinity of fine filaments, varying 

 in thickness, and giving life and motion to all these parts, we have even now only 

 a very slight and imperfect idea of this marvellous organism." 



The Agalma rulra is thus described by Vogt, a great authority. " I know," says he,. 

 " nothing more graceful than this agalma, as it floats near the surface of the waters, its 

 long, transparent, garland-like lines extended, and their limits distinctly indicated by 

 bundles of a brilliant vermilion red, while the rest of the body is concealed by its very 

 transparency ; the entire organism always swims in a slightly oblique position near the 

 surface, but is capable of steering itself in any direction with great rapidity. I have 

 had in my possession some of thes'a garlands more than three feet in length, in which 

 the series of swimming-bladders measured more than four inches, so that in the great 

 vase in which I kept them the column of swimming-bladders touched the bottom, 

 while the aerial vesicle floated on the surface. Immediately after its capture the columns 

 contracted themselves to such a point that they were scarcely perceptible, but when left 

 to repose in a spacious vase, all its shrunken appendages deployed themselves round the 

 vase in the most graceful manner imaginable, the column of swimming-bladders removing, 

 immovable in their vertical position, the float at the surface, while the different appendages 

 soon began to play. The polyps, planted at intervals along the common trunk, of rose- 

 colour, began to agitate themselves in all directions, taking a thousand odd forms ; . . - 



