Page:Hardwicke's Science-Gossip - Volume 1.pdf/264

pinned down to a loaded cork, under water all the time.

When obtained, the tubes may be mounted dry, in fluid or in balsam. The latter plan is the best, none of the others offering so much security from ultimate deterioration or damage.

From the same pond were obtained plenty of Ephemeræ larvæ, enabling me to add to the cabinet a slide of one showing tolerably well the tracheal system. A perfect specimen of this object is extremely difficult to obtain, owing to the fragility of the leaflets; but even a mediocre one is worth while. No caustic potash is necessary. The insect, after being killed in hot water, must be simply arranged, dried, and mounted in balsam. The chance of success will be the greater if it is spread out on the thin glass cover in preference to the glass slide, as is usual, and then, after drying, inverted into a drop of balsam.

When mounted, the parabolic condenser, or other dark ground illumination, will be the most effective mode of viewing, especially under the binocular microscope.

Great advantage to the mounter will be obtained if he will first look at the living larva in an animalculæ cage. This is a sight easily seen, and one of the most beautiful that the microscope can afford.

The remainder of the day was occupied in a walk to the bog at Keston, known to most microscopical observers, from the abundance of Desmidiacæ to be found there, and several hours in the evening wore spent in turning over the contents of the bottles filled from the little pools of water in the cattle tracks. Wonderful indeed they were!

About a fortnight ago, while the weather was yet fine and the treacherous sea smooth, and the breeze so gentic as scarcely to produce a ripple. on the surface of the water, I rowed from the haven at Tynemouth, to visit some wonderful caves which have been hollowed out of the limestone rocks by the action of the waves, about three miles down the coast south of the Tyne.

As I rowed along, I several times encountered magnificent specimens of the large jelly-fish, known to science by the name of Cyanea chrysuora. Few marine animals with which I am conversant are more singular and beautiful than this extraordinary creature. The umbrella-like disk, by the alternate expansions and contractions of which the animal glides along, is, in this species, marked with fine brown lines, which radiate from the centre, and the numerous tentacles and waving appendages which are suspended from the underside of the disk, float gracefully hither and thither, and but for their motion in the water would, from their delicacy and transparency, be scarcely perceptible to the sight. The colour of these highly-attenuated organs, as well as that of the other portions of the creature, being a pellucid cream, or sometimes a faint brown or fawn. Who would imagine, while gazing at these transparent, evanescent creatures, that they possess the power to inflict pain? Yet such is really the fact; hence another common name of these jelly-fishes, that of "sea-nettles." The stinging, or at least irritating, properties, reside in the tentacular appendages, and a curious instance of the smarting pain occasioned by contact with them occurred here lately. It was related to me by the boatman, who, upon observing the interest with which I examined one of the specimens, said, "Them's jelly-fishes, sir, and some of 'em stings awful." He then went on to say, that a few days ago he took a gentleman out in his boat to have a bathe in deep water, who, being a good swimmer, took a first-rate "header," and in doing so plunged directly upon tho disk of a large specimen of Cyanea chrysuora, a species to which, par excellence, the term "stinger" may be applied. The poor jelly-fish, although smashed to pieces, amply revenged its death, for as his unintentional destroyer was drying himself after his bathe, he said to the boatman, "I am afraid the water has not agreed with me this morning, for my back itches terribly;" and the pain increased so violently that, upon his return home, the victim to jelly-fish acquaintanceship found it necessary to take to his bed. The boatman, expecting what would happen, called in the course of the day to inquire after the gentleman, and, upon learning his condition, requested to be admitted, when he at once explained the cause of his suffering; upon which, as the boatman said to me, "the gen'l'man 'ops out o' bed, and says he, 'why didn't you tell me that afore?' and down he sits, and writes out a 'scripshun, which I takes to the chemist, and gets a hointment to rub his back wi'; law, sir, the jelly-fish had stung his back as red as scarlet. Hows'ever the stuff as I rubbed him wi' cured him; and by night he was all right ag'in." I have often heard people doubt the stinging properties of the Medusæ or jelly-fishes, but from my own experience of the fact, I would strongly advise bathers, who may be sceptical on this head, not to trust their limbs in contact with the tentacles of Cyanea chrysuora.W. H. Grattann.