Self Illuminators 151 



Most of us know well how in the marvellous economy 

 of Nature the sea is illuminated^ and that brilliantly 

 too, by the presence of myriads of infusoria emitting 

 phosphorescence. The slightest agitation in the sea 

 causes these marine glow-worms or fire-flies to shed 

 all the light they are capable of, and thus the passage 

 of one fish is made exceedingly obvious to another, 

 who may be pursuing him or desirous of avoiding him. 

 But this illumination varies in degree from differing 

 causes, and sometimes the sea is almost totally devoid 

 of any light. It may be, too, that as this natural 

 light is aifected in degree by certain causes operating 

 near the surface or horizontally, so it is affected by 

 vertical position. We do not know. What we do 

 know is that many deep-sea fish have, as it were, 

 their own electric light installation, row upon row or 

 group after group of tiny incandescent lamps, glowing 

 and fading at the will of their owner, rendering him 

 invisible at will or lighting up the surrounding sea so 

 that none of his intended victims may be hidden. 

 These tiny glow-lamps are arranged along the sides 

 and head of the fish in strangely regular rows or groups, 

 each differing species that possess this system of 

 self-illumination having them different. 



One thing more. In dealing with these fearsome 

 denizens of the vasty deep I must perforce use the 

 no-less appalling nomenclature given them by natu- 

 ralists, since other names they have none. For 

 this I hope, under the circumstances, I shall be 

 forgiven. 



It is a commonplace with naturalists in dealing 

 with deep-sea fish that several of their most interesting 

 species have come fortuitously to hand. No amount 

 of care or scientific appliances could have secured 

 them, and but for the accident of their coming to the 



