112 History of Luminescence 



in both the seventeenth and eighteenth centuries. Many of Bartho- 

 lin's instances of shining fish resulted from luminous bacteria, such 

 as described by Cardanus from Scotland in 1557 (Chap. Ill) . 



Many accounts of vertebrate fish luminescence would appear to 

 be very dubious. Bartholin described the " Luna," which, " by its 

 curved form and heavenly light and silvery color, reminds one of 

 the moon above the firmament and which has been observed to 

 shine at night by Gesnerus {De Lunariis, 1555) and Rondeletus 

 [De Piscibus, 1554: XV, 7) ." He noted that Jonstonus {Thanma- 

 tographia Piscum, 1632) wrote concerning herring that: " with their 

 stomachs turned toward the surface of the sea they shine in the 

 water and emanate such splendor that not only does the sea seem to 

 be brilliant but the neighboring air is illuminated . . . clear indi- 

 cation of a good haul." Such examples of shining by day are clearly 

 reflections of light from silvery skin or scales. The shining of live 

 fish at night, so often recounted by early observers, must result from 

 disturbance by the sv^^imming fish of myriads of luminous dino- 

 flagellates in the water, an effect well known to fishermen today 

 and used by them to locate schools of fish. Only if the fish were 

 dead, might their luminescence be due to luminous bacteria. 



A third false account of light has to do with the eyes of fish. 

 Olaus Magnus (Hist. XX, 29) is quoted by Bartholin ^' in connec- 

 tion " with fishing for halex [herring] in our native country. ' The 

 eyes of the halex shine like a light at night on the sea; and, what is 

 more, by the great motion of this fish and the reflection of a large 

 school it appears as if flashes and tremulous gleams were stirred up 

 on the sea, commonly called the lightning flashes of the halex!.' " ^° 

 Again these lightning flashes are probably " phosphorescence of the 

 sea," stimulated by schools of fish. 



A number of other instances of light from the eyes of marine ani- 

 mals were recorded by Bartholin. Oppianus {Halieutika, Book H) 

 spoke of the radiant eyes of the dolphin, Olaus Magnus (Hist. Sept. 

 XXI, 5) and Thevetus ^^ (Cosm. vol. II, Book 20) of the burning 

 eye of the " Limax " and Blefkenius ^^ of the sea monster, " Balena," 

 of Iceland, with fiery eyes. 



^* Bartholin, De luce anitnalium. Book II, Chap. 15. 



'" That the eyes of herring are luminous is an old belief, to be found in the Hortus 

 sanitatus of Cube (Mainz, 1484) . In Book IV, Sec. 3, there is the statement: " The 

 Herring's eyes shine by night in the sea like a light, but their virtue dies with the 

 fish." However, a later writer on herring, Paul Neucrantz (1605-1671) declared in 

 De harengo (1654, Chap. Ill, p. 20) that the brilliance of their shining eyes continues 

 several days after they are dead. 



^^ F. Andr^ Thevet (1502-1590) , the French explorer, who wrote on Antarctica in 

 1558 and a Universal Cosmography in 1571. 



** Dithmar Blefken, a German traveler who visited Iceland in 1563 and wrote a 

 description of the country in Latin. 



