No. 519] 



NOTES AND LITERATURE 



170 



on the under side of shelving rocks. There is also a blind cat- 

 fish, Ameiurus mgrilabris, which is found in caves of Lancaster 

 County, Pennsylvania. 



The best known of the blind fishes belong to the family of 

 Amblyopsida\ The genus, Chologaster, contains one species with 

 eyes, inhabiting the channels about the Dismal Swamp and the 

 rice canals of the South. The other species are known only 

 from caves and cave springs, and all the representatives of the 

 genera, Amblyopsis, Troglichthys and TyphlichtJtys, are blind. 



Dr. Eigenmann has also made an elaborate study of the blind 

 fishes of Cuba. Lu<ifng<t subtcrranai and Stygicola dentatus. 

 These two fishes belong to the family of Brotulida\ a relative of 

 the blennies. The origin of these forms is from marine fishes 

 living in clefts of coral rock. This coral rock, when raised 

 above the sea, seems to have carried these forms with it. The 

 nearest related genus, liro.miophycis. still lives among the corals. 



The details of anatomy, as well as the details of environment, 

 of each of these species, are very fully illustrated in this paper, 

 which is by far the most important one yet devoted to this 

 subject. 



Dr. Eigenmann observes in conclusion that it is absolutely 

 certain that the eaves were not peopled by a catastrophe, and, 

 further : 



That the cessation of use was gradual and the cessation of selection 

 must also have been a gradual process. There must have been ever 

 widening hounds within which the variation of the eye would not 

 subject the possessor to elimination. 



Chologaster is in a stage of panmixia as far as the eye is concerned. 

 It is true the eye is still functional, but that the fish can do without 

 its use is evident by its general habit and by the fact that it sometimes 

 lives in caves. 



The present conditions have apparently existed for many genera- 

 tions, as long as the present habits have existed, and yet the eye still 



of fishes depending on their eyes — the condition that the state of 

 panmixia alone would lead us to expect. There is a staying quality 

 about the eye with the degeneration, and this can only be explained 



The results in Chologaster are due to panmixia and the limited 



