Page:Proceedings of the Royal Society of London Vol 1.djvu/400

Rh but it does not seem probable that such a property (if it existed) could be overlooked in an animal so extremely common.

The luminous property of the Phyllis dactylus was observed by Pliny to be communicated to the hand that touched it; and this has been conﬁrmed by Reaumur.

Of the genus Elater there are three species luminous, one of which, the nactilucus, is so brilliant, that it was employed by the South American Indians for the purposes of illumination.

In the genus Lampy'ris there are many species, at the head of which is the Lampyris nactiluca, or common glow-worm, which may serve as a specimen of the manner in which the light is produced by the rest. In this species the light lasts only during the breeding season; and as it is conﬁned to the female insect, it wonld appear to answer the purpose of guiding or inviting the male. But it has been observed by Montheillard, that the eggs are also occasionally luminous; and Mr. Macartney conﬁrms this observation, as he once saw a quantity of them shine unremittineg for several days together.

Of the genus Fulgora, only three have been particularly noticed for the light they yield,-—the lanternaria, candelaria, and pyrorhyn- aims ,- although it is probable, from their structure, that many others of the genus possess this property.

The Pausus is remarkable only for the situation of its light, which is carried at the extremity of its antennae.

The Scolapendm electrica is not uncommon in this country; and yet the light has not often been observed. According to the author’s observation, the light is communicated, and remains visible for some time on a hand that has touched it; and, in one or two instances, insects which had been long conﬁned from the light did not appear luminous, but acquired this faculty after being for some time exposed to daylight.

The Cancer fulgens was discovered by Sir Joseph Banks, who ob- served that its whole body was illuminated, and produced very vivid ﬂashes of light.

01' the Monoculi, the author reckons three species that are lumi- nous; one discovered by Godeheu de Riville, and two by Capt. Horsburgh.

With respect to the Nereis nactiluca, to which the light of the sea has been ascribed by Vianelli, Griselini, Spallanzani, and others, in various parts of the Mediterrancan, and by Adleo in the African and Indian oceans, the author is of opinion that it never appears on the coasts of this country, and that the light of the sea, which we most frequently witness, is caused hy Medusae.

Of these, the largest is the Medusa pellucens, discovered by Sir Joseph Banks, along with the Cancer fulgens, in his voyage with Capt. Cook between Madeira and Rio de Janeiro. This is six inches in diameter. The noctiluca described by Taskal is three inches in diameter.

Another Medusa was discovered by Spallanzani in the Straits of Messina: it is said to be as bright as a torch, and visible at the depth