72 3 On the Phosphorescence of Marine Invertebrata. 
save ata distance. If we plunged our hands into the sea, when 
drawn out they were luminous all over, but after a few seconds, 
they were marked only here and there with bright spots, whose 
brilliancy remained constant and without scintillations. 
he bank recently left by the tide did not however show any 
trace of phosphorescence ; yet at the least shock, it became lum 
nous, and seemed literally to glow under the steps of the observer. 
In some circumstances, wherever the foot rested on the sand or 
gravel, it seemed like burning coals beneath the tread, and this ap- 
pearance was equally perfect, with more or less brilliancy, even 
to a distance of some inches. 
he Talitri, so numerous on our sandy shores, and whose hab- 
its have gained for them from the fishers, the name of sand-flea, 
become luminous by contact with the phosphorescent water,—a 
act to be noted ; for at first one might be led to imagine that 
they were the cause of the light. Nothing can be more curious 
than to see these sand-fleas leaping by hundreds, and appearing 
like the scattering of tiny sparks. 
2 J that produce the phosphorescence in the two 
preceding cases.—a. At Chausey, Brehat, St. Malo, Saint Vaast, 
have many times sought for the cause of the bright sparks, 
which I saw shining and then vanishing in darkness. In each 
case I met with living animals, and these animals were always 
Crustacea, Ophiura or Annelida. I usually found the first in the 
water drawn up either from channels or at some distance from 
the shore. ‘The second were under stones, or in the masses 0 
seaweed. It was especially to the Annelida that the Fucus owed 
its brilliancy. 
hese results explained all the circumstances of the first kind 
of phosphorescence. The Crustacea,,whose movements are enel- 
getic and whose locomotion is extended, cannot easily be collected 
in sufficient quantity on a given point to have their scintillations 
appear like auniform tint. Besides there is nothing in the habits 
of the species I have examined, to lead one to suppose that’ they 
are inclined to collect in numerous bands. The size of the 
Ophiura prevents such an idea with regard to them ; and the 
smaller Annelid for a like reason cannot contribute to such 4 
result. ‘Thus the light produced by these different animals is 
Ways Seen in points more or less near each other, but never 
really blended. 
b. At Boulogne, on the contrary, we find this brilliant light 
exclusively due to Noctiluce. With the most careful examina- 
tion, | have never found in my vases a single Annelid, or a single 
phosphorescent Crustacean. 
,, Many circumstances, some of which will be explained beyond, 
illustrate the particular mode of phosphorescence of the sea, ren 
luminous by the presence of these Rhizopodes. will 
