244 RECORD OF CURRENT RESEARCHES RELATING TO 



ratus, but in vain. When a glowworm is crushed luminous traces 

 are seen on the ground, and it has been concluded that, as in lucifer 

 matches, these were nothing else than a phosphorescent material 

 collected in the apj)aratus for the ulterior Wants of the insect. This 

 experiment is, however, very defective. If a phosphorescent glowworm 

 be dissected with needles, the fragments will remain luminous for 

 several hours at least. If on the other hand it is rapidly crushed in 

 a mortar so as to destroy the very cells, the phosphorescence im- 

 mediately disappears ; the pulp collected, exposed to the contact of 

 pure oxygen or submitted to the influence of electrical excitation, 

 remains absolutely dark. A partial crushing, therefore, allows the 

 phosphorescence to be still produced, complete crushing abolishes it. 

 On the hypothesis of a reserve of phosphorescent material, excessive 

 crushing ought evidently to favour the production of the light, by 

 spreading the material over a wide surface in contact with the air ; 

 but the contrary takes place. The phosphorescence only takes place 

 if the apparatus is divided into fragments, so that groups of cells being 

 intact continue to act. Dissection and the abnormal contact of air 

 excites the cells, and their protoplasm under these influences produces 

 the phosphorescent material at the expense of the materials which it 

 contains. If the cells be killed by crushing, life no longer inter- 

 venes to set those materials to work and give them the chemical form 

 under which the phosphorescence shows itself. 



The phenomenon is therefore of a chemical nature, but only 

 produced under biological conditions. This can be proved in another 

 manner. By submitting a glowworm to the action of sulphuretted 

 hydrogen it is immediately killed, and no light can be obtained from 

 it by electrical excitement. The cells are intact in form, but being 

 physiologically destroyed by the gas they no longer perform their 

 functions. The organ can then be pulled to pieces, acted on by 

 oxygen or electricity, without provoking phosphorescence. It is 

 certain, however, that the protoplasm contains all the materials chemi- 

 cally necessary for the production of the phosphorescent substance, 

 but this substance is not readyrmade. It is only produced in propor- 

 tion to the consumption under the influence of the will, and by the aid 

 of the nervous system, which excites the cells and causes them to act. 



The phosphorescence is therefore a phenomenon of the same 

 order as muscular movement, or the discharge of electricity in the 

 apparatus of the torpedo, which are without doubt the result of 

 chemical combinations taking place in the protoplasmic matter. 



The author considers it very probable that the phosphorescent 

 substance is a gaseous product, for the structure of the organ does not 

 give the idea of one secreting liquid. On account of the close 

 resemblance which the i^hosphorescence bears to that of decomposing 

 substances he thinks the gas is most likely j)hosphuretted hydrogen. 

 As the result therefore of his observations on the glowworm and 

 Noctiluca, he considers phosphorescence to be a general property of 

 protoplasm, consisting in a disengagement of phosphuretted hydro- 

 gen. It can thus be understood how it is that many of the lower 

 animals which are without a nervous system are phosphorescent. 



