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Popular Science Review, where I knew there was an article by the celebrated naturalist, De Quatrefages, on this very subject. The article is far too long for reproduction in Science Gossip; but some of the readers may perhaps feel interested in knowing that M. De Quatrefage's experiments tend to show that the luminous appearance is owing to the presence of living creatures, called Noctilucæ. Many theories seem to have obtained credence from time to time. The article in question says, "Ancient navigators appear to have attributed the light which is developed on the surface of the water to what may be termed 'ordinary causes,' and they believed it to be due to various atmospheric phenomena. To them phosphorescence was the meteor of the sea. Abbé Nollet sees in it nothing more than a modification of electrical phenomena. Bujon refers it to a disengagement of electricity. Tingry compares it to the fluorescence of the diamond, and thinks that the sea absorbs solar light during the day, which is liberated at night. It has also been attributed to 'phosphoric fires,' and to the ignition of bubbles of hydrogen bursting at the surface of the water, &c., &c. As far back, however, as 1705, Professor Viviani, of Genoa, discovered fourteen species of luminous animalculæ. To their presence be attributed the phosphorescence of the seas of his country. In our day everything tends to prove that the sea possesses its phosphorescent fauna, as does the land." Some of M. De Quaterfages' experiments were very striking.

He says, "I took some water from a very brilliant wave, and with it filled a tube one decimetre (about four inches) in height. After it had been permitted to stand a few minutes, the layer formed by the aggregation of Noctilucæ was one and a half centimetres in thickness; consequently, the animalculæ constituted a seventh of the whole mass of fluid." He also says, "I have subjected luminous water to filtration (a rather find handkerchief suffices for the experiment). The Noctilucæ remained in the linen, to which they imparted a brilliant light, whilst, on the other hand, the filtered liquid presented no signs of phosphorescence, notwithstanding every means employed to promote it." Some of our readers may, perhaps, be interested in his description of the animal. He says, "The Noctilucæ are microscopical animalculæ, bearing a pretty general resemblance to little melons deeply indented at one end. Near this depression is fixed an appendage, which the animalcule moves slowly to and fro, swaying from right to left. The body is so completely transparent as to admit of its structure being studied in its minutest details. Near the appendage these membranes present a minute orifice, which serves as the outlet for a little mass of pellucid, homogeneous, and finely granulated substance, which is prolonged into the internal part of the body. From the mass which forms, as it were, a centre, there radiate in every direction a number of extensions, which become more and more ramified as they proceed, and of which the ultimate indefinitely multiplied ramifications spread themselves over the whole inner surface of the animal." M. De Quatrefages then describes the animal very minutely, and adds, "Examined by a power of twenty or thirty diameters, the illuminated portion of the body of the Noctilucæ presents a uniformly bright aspect. With sixty diameters, a number of small but brilliant scintillations become visible, detaching themselves, as it were, from parts of what appears to be a pale luminous background, and these scintillations come and go with the rapidity of lightning. An enlargement of one hundred and fifty diameters, however, reveals the true character of the phenomenon. It then becomes obvious that the light emitted from the whole body, or any of its parts, is composed of a vast number of instantaneous scintillations, closely approximating to one another at the centre of the "phosphorescent" portions but disseminated and clearly distinguishable at the edges. Occasionally there may be seen isolated sparks at the extreme limit of the luminous part, or even beyond it. Those of our readers who care to go further into this subject will do well to consult M. Quatrefages' article.

Many and many a visit has the writer paid to this pretty neighbourhood, and very many have been the microscopical treasures there found.

One day last summer, being unable to get a companion, he set out alone, resolved to make the best of circumstances, such as they were. No sooner had the train started than it began to rain, and it continued raining, sometimes heavily, during the rest of the day; being provided, however, with a waterproof cape, the inconvenience was not great.

Diptera, &c., being scarce in such weather, there was no alternative but to search the horseponds and ditches in the vicinity of the path, in the hope of obtaining aquatic larvæ.