Far Eastern and Classical Antiquity 25 



prompted to this view by a certain sensory affection of whose true cause 

 they are ignorant. This is that, when the eye is pressed or moved, fire 

 appears to flash from it. This naturally takes place in darkness, or when 

 the eyelids are closed, for then too, darkness is produced. 



The various subjective light phenomena connected with the human 

 eye must have greatly influenced Greek theories of vision, some of 

 which regarded emanation from the eyes as responsible for seeing. 



Another possible reference to luminous bacteria on fish is found 

 in Aristotle's discussion of sensation, De Sensu. In the second chap- 

 ter, which deals specifically with light and vision, we find,^^ " It is 

 the nature of smooth things to shine in the dark as e. g. the heads 

 of certain fishes and the juice of the cuttle-fish." The " juice " of 

 the cuttlefish is particularly interesting. In addition to luminous 

 bacteria, which often grow on the surface of dead squid, some 

 forms (Sepiola and Rondeletia) have open luminous glands and 

 frequently harbor luminous bacteria, while one remarkable deep- 

 water species (Heteroteuthis dispar) actually discharges a brilliant 

 luminous secretion that could be referred to as a " juice." The 

 word tholos which is translated by " juice," really means the dark 

 ink, or sepia, of the cuttlefish, from which the Greek verb tholo, " to 

 make turbid," is derived. The luminous secretion of the deep-sea 

 squid, Heteroteuthis, practically takes the place of the inky juice of 

 other squid and the word tholos might be applied to it. It seems 

 highly probable that Aristotle knew of Heteroteuthis, which is 

 caught even today by the fishermen of Sicily near Messina, in the 

 neighborhood of Charybdis, the whirlpool so fatal to the fleet of 

 Ulysses. In this region they are carried upwards by currents from 

 deeper waters and may actually swim at the surface of the sea. Other 

 luminous marine animals (jellyfish, sea pens, Pholas) are not men- 

 tioned specifically, but Aristotle did refer to the light which appears 

 when one strikes the sea with a rod at night, as explained in a 

 subsequent section. 



The firefly and glowworm occur in Historia AnimaUum. In 

 D'Arcy Thompson's translation the following statements will be 

 found: " Some insects are wingless . . . ; some are winged . . . ; and 

 the same kind is in some cases both winged and wingless, as the ant 

 and the glow-worm." ^* Also, " From a certain small, black and 

 hairy caterpillar comes first a wingless glow-worm; and this creature 



^^ The original Greek and a translation of De sensu and de memoria, 49, by G. R. T. 

 Ross, Cambridge Univ. Press, 1906. Another translation by J. I. Beare (1908) , reads: 

 " For it is in the dark that that which is smooth, e.g., the heads of certain fishes and 

 the sepia of the cuttle fish, naturally shines. . . ." 



^* Historia animalium, ed. by J. A. Smith i.nd W. D. Ross 4, Book IV, 523b 21, 

 Clarendon Press, 1910. 



