DR. GUNTHER ON THE STUDY OF FISHES. 389 



over the retina-like membrane or the glandular follicles. The former 

 kind of organs are considered by some naturalists true organs of vis- 

 ion (accessory eyes), the function of the latter being left unexplained 

 by them." 



There can hardly be a reasonable doubt that the functions of these 

 organs, of both kinds, have reference to the conditions of light under 

 which the animals live, but further than that judgment concerning 

 them must be suspended. Dr. Gtinther briefly states three hypotheses 

 that have been broached as possible : 1. That both kinds are " acces- 

 sory eyes," to which the objection is offered that several fish having 

 well-developed and even large eyes, perfectly adapted for seeing in 

 the dark, are endowed with them, while in other deep-sea fishes, with- 

 out external eyes, they are absent. 2. That only the organs with a 

 lenticular body and a retina-like membrane behind it are visual, but 

 that the glandular organs are phosphorescent ; and more may be said 

 for this view than for any other, since the glandular organs are cer- 

 tainly luminous. 3. That all the organs are producers of light, in 

 which case it must proceed from the inner cavity and be emitted 

 through the lens-like body as through a bull's-eye lantern. It will be 

 hard to decide which of these suppositions is the right one, for it seems 

 impossible to reproduce in the animals and their environment on the 

 surface the conditions of an uninterrupted deep-sea life. [This sub- 

 ject was fully discussed by Dr. Ernest Krause in the last number of 

 " The Popular Science Monthly."] 



The deep-sea fishes display few colors. Their bodies are generally 

 black or silvery, with a most brilliant sheen, which is preserved even 

 after years of immersion in spirits. A few are " picked out " with 

 bright scarlet, either on the fin -rays or the filaments attached to them. 

 These filaments, it may be said, are eminently characteristic of fishes 

 that inhabit still water, and the fact that many of the deep-sea forms 

 are adorned with them perfectly accords with the belief that the abys- 

 mal regions are quiet. 



Another remarkable property of some of these creatures is the pos- 

 session of a stomach so capable of distention that it can hold a prey 

 of twice or thrice the bulk of its destroyer. Dr. Gtinther gives figures 

 of two or three fish with distended stomachs ; and Mr. Johnson, his 

 associate in this investigation, writes of a specimen which he procured 

 at Madeira : 



" The man from whom I obtained it stated that he had a fish with 

 two heads, two mouths, four eyes, and a tail growing out of the middle 

 of the back, which had astonished the whole market ; and the fisher- 

 men, one and all, declared they had never met with anything like it 

 before. At first sight it really did appear to be the monster described; 

 but a short examination brought to light the fact that one fish had been 

 swallowed by another, and that the features of the former were seen 

 through the extensible skin of the latter. On extracting the fish that 



