FINIfY LIQHT-BEARERS. 95 



quently fringed at its extremity, it evidently serves as a lure 

 for other fishes or animalculte. Series of luminous, globular 

 bodies run along the lower half of the body and tail ; and 

 some others of larger size occupy the side of the head, gener- 

 ally below the eye or behind the maxillary bone. This fish 

 is sixteen inches in length. The end of the barbel, which 

 was thickened, was flesh-color with a rose tint; there was 

 also a rose tint on the dorsal and anal fins. The rest of the 

 animal was of a dark color. The phosphorescent spots along 

 the belly and radial and lateral line were red, as was also 

 that below the eye." 



It is not often that the light of these fishes is seen ; 

 but the late Professor Willemoes Suhm, while watching the 

 great trawl come over the side upon a calm night, noticed 

 a gleaming spot, and taking it out found it to be the little 

 fish Sternoptyx. In referring to it he says, " It hung in the 

 net like a golden star, as it came out of the darkness." 



As the Sternoptyx is a delicate little creature, and quite 

 defenceless, its illumination must be a fatal gift. This is 

 equally true of the Argyropelecus hemigymnus (Plate X., Fig. 

 3), a curiously formed fish, — deep in the body, tapering 

 off suddenly to the tail, as if a piece had been bitten out by 

 some large fish. Referring to the figure, it will be seen that 

 the luminous organs are grouped ; four being at the side of 

 the tail, six midway between it and the line of the dorsal fin, 

 and many others around the edge of the ventral surface, — 

 one hundred and six in all : so that if all these plates are 

 luminous, the Argyropelecus must present a dazzling sight 

 as it darts along in the blue waters of the Mediterranean, 

 where it has been most commonly observed. 



Concerning the functions of these organs, there is still 



