Observations upon Luminous Animals. 25 
to certain animals, that either do not possess it, or in which 
its existence is questionable. I shall next give an account 
of some Juminous species, of which some have been inac- 
curately described, and others quite unknown. I shall en- 
deavour to explain from my own observations, and the in- 
formation communicated to me by others, many -of the 
circumstances attending the luminous appearance of the 
sea. I shall then describe the organs employed for the 
production of light in certain species; and lastly, I shall 
review the opinions which have been entertained respecting 
the nature and origin of animal light, and relate the experi- 
ments T have made for the purpose of elucidating this part 
of the subject. 
The property of emitting light has been reported to be- 
Jong to several fishes, more particularly the mackarel, the 
moon-fish (tetraodon mola), the dorado, mullet, sprat, &c., 
Mr. Bajon observed during the migration of the dorados, 
&c. that their bodies were covered with luminous points. 
These, however, proved upon examination to be minute 
spherical particles that adhered to the surface of these fishes; 
and, he adds, appeared to be precisely the same sort of 
points that illuminated the whole of ihe sea at the time. 
They were therctore im all probability the minute kind of 
medusa, which I shall have occasion to describe hereafter. 
Godeheu de Riville states, in a paper sent to the Academy 
of Sciences at Paris, that on opening the sconiber pelamis 
while alive, be found in different parts of its body an oil 
which gave out much light: but it should be observed, that 
Riville had a particular theory to support, for which this 
fact was very convenient, and that other parts of his me- 
moir bear marks of his inacenracy. It. may be added, that 
if the oil of fishes were usually luminous, which Riville 
supposcd, it would be almost universally known, instead of 
resting on a solitary observation. 
As far as I am able to determine from what I bave seen, 
the faculty of exhibiting light during life does not belong to 
the class of fishes. It appears probable, that some fishes 
may have acquired the character of being luniinous, from 
evolving light soon after death. 
Some species of Iepas, murex, and chama, and some 
star-fish have been said to possess the power of shining; 
and the assertion has been repeated by one writer after an- 
other, but without quoting any authority. 
Brugueire upon one occasion saw, as he supposed, com- 
mon carthworms in a luminous state; ail the hedges were 
filled 
