THE PHOSPHORESCENCE OP THE SEA. 297 
Tlie contents of these cells, he says, “ are albuminous they do not con- 
tain “ phosphorus,” as was stated by Leydig, another observer, hut a uric 
acid salt, probably urate of ammonia. This latter discovery Koelliker put to 
the strictest chemical tests, always with corresponding results ; and, on the 
other hand, he satisfied himself, by the employment of other tests, that no 
phosphorus was present. 
Koelliker believes the luminosity of the glow-worm to be dependent on the 
will of the animal, but not (as De Quatrefages regards that of Noctiluca, the 
marine Annelides, &c.) to be at all influenced by movements. He says, 
“ Even in the night-time, individuals may be noticed performing the most 
active movements, and yet showing no luminosity whatever.” 
He tried the effects of various irritants — mechanical, electrical, thermal, and 
chemical ; indeed, from the account which he gives of his various experi- 
ments, lie seems to have treated the glow-worm much in the same manner as 
De Quatrefages tested the luminosity of his little Protozoans, and his con- 
clusions are “ that the luminous organs are a nervous apparatus whose nearest 
analogues may be sought in the electrical organs” (of fishes, such as the Elec- 
trical Eel, Gymnotus, &c.) 
“ All excitants of the nerves excite the luminosity, and the agents which 
annihilate the nervous functions act injuriously in this case also. My experi- 
ments wholly subvert the theory hitherto current, which assumes the exist- 
ence of a luminous material secreted and deposited in the organs, a sort of 
phosphorus, which on the addition of oxygen through the respiratory move- 
ments becomes oxydized, and consecpiently luminous.” 
After showing that the tests applied by him prove that no such substance 
can be present, he concludes by stating that “ the light is produced under the 
influence of the nervous system, and in all cases is maintained only for such a 
period, whether long or short, as the nerves, stimulated by the will or other- 
wise, act upon the organs.” 
The reader will perceive, therefore, that although this account of the 
luminous organs in insects (so far at least as the glow-worm is concerned) is 
at variance with the theory adopted by our able contributor regarding that 
class of animals, yet it is confirmatory of his conclusions that phosphorescence, 
or, more correctly speaking, “ animal luminousness,” is the result of vital and 
not of physical action. And, moreover, the investigations of these two inquirers 
may suggest to some of our readers, as they have done to its, the probability 
that the phenomenon observed by the one in the Annelides and in Noctiluca, 
and by the other in Lampyris, may be of a like nature. That is to say, it is 
quite within the range of probability that both may result from, or be 
influenced by nervous action, and that the “ scintillations” so beautifully 
described by M. Quatrefages may have taken their course along the motor 
nerves. 
This is an inquiry of great importance to physiologists, for if it can be 
established that luminosity is invariably related to nervous action (when 
there is no perceptible secretion of phosphorescent matter), it will necessarily 
follow that Noctiluca, and probably all the lowest forms of animal life in 
which no nervous system has yet been traced, possess at least the rudiments 
of one ; and this is rendered still more probable in consequence of the diffused 
or pervading character of the luminosity in the lowest forms, as in Noctiluca 
