84 THE NATURE OF ANIMAL LIGHT 



Bermuda, which is brilliantly luminous while swarmin 

 when the eggs and sperm are shed. It is non-luminou 

 at other times (Galloway and Welch, 1911.) 



(4) Finally, it is possible that animals with com 

 plex luminous organs, such as squid, fish and shrimp 

 actually use these as lanterns. It is significant that mos 

 of them are deep sea forms, living in a region of perpetua 

 darkness, and it is perfectly logical to suppose that the^ 

 Vake use of their light organs for illuminating purposes 

 " The whole problem of the use and purpose of luminoui 

 organs is an exceedingly complex and difficult one. W( 

 have, perhaps, said enough to indicate this and may adc 

 that in most cases, so far as opinion is based on actua 

 evidence and observation, that of the layman is of as 

 great value as that of the scientist. 



