upon Luminous Animals. 281 
moment, and these exhibit a phosphoric light for a few seconds 
afterwards. This fluid, however, I never could discover in the 
form of moisture, even upon the clearest glass, although 
examined immediately with the most scrupulous attention by 
a lens : it must therefore be extremely attenuated. 
The same appearance has been observed during the illumi- 
nation of the nereis noctiluca by Fougeroux de Bondaroy.^ 
The animal discovered by Riville shed a blue liquor,, 
which illuminated the water for a distance of two or three 
lines.-f 
Spallanzani relates, that the medusa which he examined, 
communicated the property of shining to water, milk, and 
other fluids, on being rubbed or squeezed in them.£ 
The luminous fluid is in some instances confined to par- 
ticular parts of the body, and in others is diffused throughout 
the whole substance of the animal. 
In the scolopendra electrica, it appears to reside immediately 
under the integuments. In the lynceus discovered by Riville,, 
it is contained in the ovary. If I may judge from my own 
observations, every part of the body of the medusae is fur- 
nished with this fluid, as there is no part I have not seen 
illuminated under different circumstances, but Spallanzani 
affirms that it is only found in the large tentacula, the edges 
of the umbella, and the purse or central mass; which he 
proved, he says, by detaching these parts successively, when 
they shone vividly, while the rest of the body neither gave 
light or communicated any luminous appearance to water.§ 
* Mem. de 1’ Acad, des Sc. 1767. 
f Mem. Etrang. de i’ Acad, des Sc. Tom. iii. 
X Spallanzani’s Travels in the Two Sicilies, Vol. iv. 
§ Memoria sopra le meduse fcsforiche. Mem. della Soc.Ttal. Tomo viL 
