8 LIVING LIGHTS. 



to see the face of a watch and read the figures ; and, if the 

 little creatures were agitated, time could be ascertained 

 at a distance of a foot. M. Quatrefages found that the 

 most delicate thermometer was not affected by the light ; 

 and he assumes that it is not combustion from the fact that 

 oxygen gas, when introduced, does not restore the light after 

 it has disappeared at the death of the animal. His conclu- 

 sion is, that the light is produced by the contracting of the 

 interior mass of the body ; and that the flashes, or scintilla- 

 tions, are due to the rupture and rapid contraction of the 

 filaments of the interior. The fixed light he explains as 

 resulting from the permanent contraction of the contractile 

 tissues adhering to the inner surfaces of the general envelope. 

 Giglioli is especially enthusiastic over the light of the Nocti- 

 luccB and other forms ; and to show its general distribution 

 he says that in fifty-five thousand marine miles traversed 

 by the " Magenta," the Italian exploring-ship, in four hun- 

 dred and thirty-nine days, phosphorescence was observed 

 more than half of the time. He met Noctilucce in the Bay 

 of Naples, at Rio, in the Straits of Banca, while in the east 

 coast of Asia ; and at Port Jackson " the same milky uniform 

 light was seen, without any green or bluish tint," and again 

 at Valparaiso. He observed, including Noctiluca miliaria, 

 three luminous forms, all differing in the color of their light. 

 The one observed on the Asiatic coast emitted a green 

 light, and is called by M. Giglioli, N. homogenea. The Pacific 

 form, N. pacifica, has a whitish luminosity, and differs from 

 the others materially in form and structure. 



In many of the ports of tropical and semi-tropical America, 

 it is the custom to bathe in the ocean at night, the warmth 

 of the water rendering such recreation enjoyable. A gentle- 



