22 ART. 15. II. OIISIIIMA : SOME OBSERVATIONS 



(e) No spontaneous luminescence has been observed. 



Before concluding I may say a few words concerning the 

 œcological meaning of the luminous organs of fishes discussed 

 by Brauer. 



As regards the frightening purpose, Brauer states that 

 it is possible only in the case when '' entweder das Sekret 

 herausgespritzt würde oder blitzartig auf einen Reiz hin auf- 

 leuchten würde." According to my experiments, the latter holds 

 good for 3lyctopliu7n, in which the photophores, especially the 

 large anteorbital organs, glitter spark-like upon stimulation, so 

 that it must be quite useful for frightening purposes, contrary to 

 his statement that "die zweite scheint mir deshalb nicht vorhanden 

 zu sein, weil nach den Beobachtern das Licht gleichmässig in 

 allen Organen auftritt, usw." 



As to the use of the organ for illuminating purpose, that 

 seems to occur only in Anomalops and Photoblepharon, in which 

 the organs are placed inferiorly to the eyes and emit quite intense 

 and continuous light. Such cases are not found in any other 

 group of luminous fishes. 



Tokyo, Feb. 7, 1910. 



