540 



PHOSPHORESCENCE. 



noise proceeded. As soon as I found that it came 

 from the box, I opened it, but was still more alarmed, 

 and let it fall to the ground in my fright, at seeing a 

 flame of fire come out of it; and as many animals as 

 came out, so many different flames appeared. W hen 

 I found tliis to be the case, I recovered from my 

 alarm, and again collected the insects, much admiring 

 their splendid appearance." The light, she adds, 

 of one of these insects is so bright, that a person 

 may see to read a newspaper by it. We have given 

 a representation of the punctated lantern-fly (fulgora 

 jjunclald) pi. '28, fig. 87. 



There is an insect of the Myriopodous order, the 

 electric centipede (scolopendra electrica), a native of 

 'Britain, which has the property of emitting a phos- 

 phorescent light in the dark. The insect is extremely 

 plentiful, but it seldom leaves its hole in the ground 

 during night. When it crawls about at night, it 

 leaves a tract of phosphorescent light which may be 

 lifted. 



Dr Afzelius discovered that thepausus spherocerus, 

 an insect of the caleopterous order, yields light. 

 One evening, on going to look at his insects, he 

 happened to stand between the candle and the box, 

 so that his body cast a shadow upon the insects; he 

 was much astonished to find that the globes of the 

 antennae shone like two lanterns, emitting a pale, 

 phosphorescent light. During- the course of that 

 night he examined the animal several times, when 

 it always presented the same appearance. He was, 

 however, prevented making experiments on it, as it 

 died before morning, and he never could find another 

 living specimen. 



Fig. 33 is the night-shining nereis (N. noctiluca) 

 greatly magnified. This animal was discovered by 

 Vianelli. Its natural size is only a quarter of an 

 inch. It is also certain that it yields a shining light. 

 Vianelli noticed that there was light emitted from it 

 at all seasons, but that it was stronger and more 

 frequently to be seen in summer. He also observed 

 that when the wind was about to change from south- 

 east into the east, the intensity of the light was increas- 

 ed, and in the dark winter nights which succeeded a 

 warm sun, the luminous appearance was as strong as 

 in summer. Bondaroy says, this species increases, 

 diminishes, or extinguishes its light at pleasure, and 

 that it commonly issues from the posterior part of 

 the body; but when fully illuminated, the head only 

 is opaque. The light emitted by it is of a bluish 

 colour. 



These minute creatures inhabit every sea, and are 

 one of the causes of the luminosity of the water in 

 the night. They are found on all kinds of marine 

 plants; but often leave them, and swim on the sur- 

 face of the water. They are frequent at every 

 season of the year, but particularly in summer, before 

 stormy weather, when they become more agitated 

 and more luminous than at other times. So small 

 are they that myriads of them may be contained in 

 a small cup of sea-water. Innumerable quantities 

 of these animals lodge in the cavities of the scales 

 of fishes ; and to them, probably, many fishes are 

 indebted for their luminous quality. " I have ob- 

 served with great attention," says Barbut, " a fish 

 .just caught out of the sea, whose body was almost 

 covered with them, and have examined them in the 

 dark. They twist and curl themselves with amazing 

 agility; but soon retire out of our contracted vision, 

 probably on account of their glittering numbers 

 dazzling the eye, and their extreme minuteness 

 eluding our researches. It is to be observed that, 

 when the unctuous moisture which covers the scales 

 of fishes is exhausted by the air, these animals are 

 not to be seen; nor are the fishes then noctilucous, 

 that matter being, perhaps^ their nourishment when 



living, as they themselves afford food to many marine 

 animals. 



The appearance of the nereides is particularly 

 brilliant when the wind is in the east and south-east 

 points; and in winter nights preceding a warm day. 

 If water containing these animals be kept warm, 

 they will retain their luminous appearance two whole 

 days after they are dead; but in cold weather they 

 lose it in the course of seyen or eight hours. Motion 

 and warmth, which increase their vivacity and 

 strength, increase also their luminous properties. 



Fig. 48 is the nereis phosphor 'anus, aluminous mol- 

 lusca, which inhabits the African and Indian seas. 



Fig. 19 represents the animalcule discovered by 

 Forster greatly magnified. 



Fig. 18 is the beroe fulgens, size of life. This 

 animal was discovered by Macartney, and is here 

 represented in the elongated form which it assumes 

 while in the act of swimming; on the posterior part 

 are seen the ciliated ribs, which constitute its in- 

 struments of locomotion. 



Fig. 27 is the cancer fulgens, represented in the 

 natural size. It was discovered by Sir Joseph Banks, 

 in his voyage with captain Cook, in the passage from 

 Madeira to Rio de Janeiro; he noticed that its whole 

 body was illuminated, and emitted very vivid flashes 

 of light. 



Fig. 51 is ihesimulus noctilucus, greatly magnified ; 

 which was discovered by Captain Horsburg. 



Fig. 32 is a crustaceous animal discovered by 

 Riville, showing the transparent shell through which 

 the internal parts of the animal are visible : the 

 horse-shoe-shaped appearance shows the sac contain- 

 ing the intestines; in front are seen the four-jointed 

 setaceous antenna} ; and on the right side are ex- 

 hibited the feet armed with hooks; lower down is 

 the larger hind foot; the small round specks repre- 

 sent the ova, which were mistaken by Riville for 

 globules containing an oily fluid. 



Many species of medusas exhibit a strong light; the 

 most splendid of these with which we are acquainted 

 is the pellucens, fig. 20; which was taken from the 

 sea at the same time with the cancer fulgens, by Sir 

 Joseph Banks, in the passage from Madeira to Rio 

 de Janeiro. The medusa pellucens emits Bashes of 

 light during its contractions, which are so vivid as 

 to affect the sight of those who witness it. When 

 the water, in which these animals and the cancer 

 fulgens were contained, was emptied out of a bucket, 

 it appeared like a stream of fire, or fused gold. 



Spallanzani discovered a medusa in the strait of 

 Messina, which he describes as being exceedingly 

 luminous ; he says, it blazes like a torch, and is 

 visible thirty-five feet under the surface of the water. 

 Its light, however, is variable; sometimes it con- 

 tinues for a quarter or half an hour, and even longer; 

 at others it becomes suddenly extinct, and re-appears 

 after a considerable interval. He accounts for this 

 cessation by supposing that it is while the animal is 

 at perfect rest. We must remark, that it is curious 

 that the above striking appearance has not been 

 recorded since the time of Spallanzani. 



Fig. 17 is the medusa scintillans, greatly magnified 

 which shows the opaque parts upon the sides, and 

 centre of the animal. The two small globules below 

 this figure represent the animals in the natural size. 



Fig 16 is a figure of the medusa lucida, the size 

 of the largest specimens which are to be met with. 



Fig. 20 is the medusa pellucens, which was discov- 

 ered by Sir Joseph Banks; about one fourth the 

 natural size. 



Riville, while on the coast of Malabar, noticed 

 that the sea around his vessel exhibited a brilliant 

 phosphorescent appearance; he caused some water 

 to be drawn up, and having strained it, it no longer 



