Sept. 1, 1870.] 



HARDWICKE'S SCIEN CE- GOSSIP. 



195 



smaller Acalephr.; so while the boat glides smoothly 

 on, let us take a brief glance at what Professor 

 Owen and others have told us about them, so that 

 when we have taken them we may not simply ad- 

 mire them in ignorant wonder as curious objects, 

 but may have some slight general idea of their 

 economy, their life history, and their place in Nature. 

 Ignorance will ever cry Cui bono? Superstition 

 will cry Beware ! beware of the tree of knowledge ! 

 beware of the pursuit of truth ! forgetting how men 

 of old were condemned because they loved darkness 

 rather than light. Good, pious, well-meaning 

 dunces, listen to . the words of one who was at 

 least equal to you in all goodness, and immeasur- 

 ably superior to you in wisdom and intelligence. 

 " There is no danger to profound these mysteries, 

 no sanctum sanctorum in philosophy : the world was 

 made to be inhabited by beasts, but studied and 

 contemplated by man : 'tis the debt of reason we 

 owe to God, and the homage we pay for not being 

 beasts. The wisdom of God receives small honour 

 from these vulgar heads that rudely stare about, 

 and with gross rusticity admire his works ; those 

 highly magnify Him, whose judicious inquiry into 

 his acts, and deliberate research into his creatures, 

 return the duty of a devout and learned admiration." 

 — Religio Medici, A.D. 16S6. 



"The Acaleplice are remarkable on account of the 

 peculiar nature of their tissues, which are often as 

 transparent as the purest crystal, and seem more 

 like the vitreous humour than any other in the 

 higher classes ; they are not less interesting for the 

 elegance of their forms, the beauty of their colours, 

 and for the peculiar property which many of them 

 possess of stinging and inflaming the hand that 

 touches them ; whence the term aica\i]§r], applied 

 to them by the ancient Greek naturalists, and " sea- 

 nettles" by our fishermen and sailors. They are re- 

 presented on our own coasts by numerous discoid 

 and spheroid species, varying in size from an almost 

 invisible speck to a yard in diameter, and which, 

 besides the vernacular name above cited, are known 

 as "sea-blubbers," "jelly-fish," or by the Linnsean 

 generic term " Medusa." This class has been divided 

 into Physogrades (tpvaiyZ, a bubble, and gradior, I 

 proceed), floating by means of air-bladders, like the 

 familiar Portuguese Man-of-war ; Ciliogrades, which 

 propel themselves by the action of their external 

 cilia; and Pulmogrades (lung-walkers), which swim 

 by the contractions of the umbrella - shaped re- 

 spiratory disc ; the common Rhizostoma Cuvieri for 

 example. The terms Siphonophora, Ctenop/iora, and 

 Discophora, are substituted by some authors for 

 those given above. 



Our young friends are probably familiar with 

 that commonest of polyps, the Hydra viridis, which 

 is to be found hanging down from the under side of 

 the floating duckweed on every pond, and they 

 know how it catches its living prey with its snaky 



arms, and multiplies by gemmation almost like a 

 plant. Now, the lower forms of our Acalephce are 

 very closely related to the humble polyps ; indeed, 

 the lowest Medusa is little else than a Hydra with 

 an umbrella. Here (fig. 176) is one of them, which 

 will serve to show the general plan of construction 

 of the Naked-eyed Medusa? better than any lengthy 

 description. 



Fig. 1/6. Thaumantias Pilosella. 



In fig. 176 (a) shows the buccal arms, or oral 

 tentacles forming the lips ; (b) the stomach. An 

 oesophagus leads from the mouth to this gastric 

 cavity, which is altogether an improvement upon 

 the mere bag of the hydra. Erom its upper end four 

 gastro-vascular canals (c) radiate towards the 

 margin of the disc, and communicate with' the 

 circular marginal canal (d), which carries the 

 nutrient fluid right round the body. On either side 

 of the radiating canals are placed the ovaries (e) ; 

 and certain excrementitious orifices, first discovered 

 by Ehrenberg, are situated at equal distances on 

 the margin of the disc. " In the higher animals we 

 are accustomed to find the nutritive apparatus com- 

 posed of several distinct systems, one set of organs 

 being destined to the prehension of food, another 

 to digestion, a third to the absorption of the 

 nutritious parts of the aliment, a fourth provided 

 for its distribution to every part of the body, and a 

 fifth destined to insure a constant exposure of the 

 circulating fluid to atmospherical influence. These 

 vital operations are carried on in vessels specially 

 appropriated to each; but, in the class of animals of 

 which we are now speaking, we find but a single 

 ramified cavity appropriated to the performance of 

 all these functions, and exhibiting, in the greatest 

 possible simplicity, a rough outline, as it were, of 

 systems afterwards to be more fully developed." 



Ten minutes have elapsed since the net was 

 " hove," so we light the lantern, put about a pint 

 of salt-water into the basin, and, in the midst of a 

 breathless silence, we draw in our line, and carefully 

 lift our frail apparatus over the gunwale, and 

 deposit it on the bottom-boards. All eyes are 

 riveted upon it, and some one is rather shy of it, 

 turns a little pale, and evidently thinks it the least 

 bit "uncanny;" pale blue, deathly -looking flames, 

 like the baleful corpse-lights Mrs. Crowe used to 

 find flickering round the fearful old churchyards 



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