402 FISHES 



tributed rather to such habits than to the conditions of abyssal 

 life in general. The presence of eyes in other deep-sea fishes, 

 these organs being often not reduced but enlarged, indicates 

 the presence of light, which is believed to be produced by the 

 luminous organs of the fishes themselves and of other animals. 

 The blind species were obtained from depths between a 

 thousand and two thousand fathoms in the Pacific and Indian 

 Oceans. Garman has also described a species Leucicorus lus- 

 ciosus from a depth of nearly two thousand fathoms in the 

 Pacific in which the eyes are rudimentary and apparently func- 

 tionless, iris and pupil being absent and the eyeball collapsed ; 

 this fish also belongs to the Zoarcidae. The condition of 

 Ipnops and its relation to the Myctophidae have been described 

 in the section on phosphorescent organs ; eyes in this fish have 

 apparently disappeared without leaving a trace, as there is no 

 evidence to confirm the suggestion that the supposed phospho- 

 rescent organs are modified eyes. 



Among the abyssal fishes discovered in the expedition of 

 the Investigator in the Bay of Bengal, Alcock describes a 

 deep-sea angler named Onirodes g/owerosus with rudimentary 

 eyes covered by the skin : it is only about 2 in. long, and is 

 one of the species in which the dorsal tentacle carries a lumin- 

 ous organ. It came from 1260 fathoms. He also obtained a 

 blind skate, Benthobatis moresbyi, dredged at 430 fathoms off 

 the Travancore coast : the eyes in this species were too much 

 reduced to be of any use, yet it had a row of luminous organs 

 along the edge of the body. What can be the use of light to a 

 blind fish? Probably it serves to attract small fishes or other 

 animals which serve as food. 



The only other fish, besides the cave-fishes and deep-sea fishes 

 mentioned, which is totally blind, is a species named Typhlo- 

 gobius calif orniensis ; this is a small goby from 2 to 3 in. in 

 length, said to be most nearly allied to Crystallogobius nillsonii, 

 a transparent small fish which is common at depths of about 

 thirty fathoms off the British and Irish coasts. Typhlogobius is 

 found only in holes in the mud under stones at Point Loma, 

 San Diego, California : the holes are excavated by a burrowing 

 shrimp which lives in them in company with the fish. Both 

 the animals are of a similar pink colour but the shrimp is not 

 blind. It is a curious fact that according to Professor Eigen- 





