LIGHT PRODUCTION IN CEPHALOPODS. 163 



Although it was taken from a considerable depth, he was able to 

 keep it alive in ice water long enough to make a photograph of it 

 by dint of its own light. Again I must quote from a translation 

 by Hoyle : "Among all the marvels of coloration which the animals 

 of the deep sea exhibited to us, nothing can be even distantly 

 compared with the hues of these organs. One would think that 

 the body was adorned with a diadem of brilliant gems. The 

 middle organs of the eyes shone with ultramarine blue, the lateral 

 ones with a pearly sheen. Those towards the front of the lower 

 surface of the body gave out a ruby-red light, while those behind 

 were snow-white or pearly, except the median one, which was 

 sky-blue. It was indeed a glorious spectacle." It is altogether a 

 pity that similar observations have not been possible for the 

 doubtless even more spectacular Nematolampas regalis, which, 

 although very nearly related to Lycoteuthis is equipped with an 

 entire further battery of photophores. 



More detailed from the standpoint of physiology is the account 

 given by Watase (105) of a little squid, the "hotaru-ika" of 

 Japanese writers, 1 which is extremely abundant at the proper 

 season and locality on certain of the shores of Japan, and which 

 has since become the best known of all the luminous squids. 

 Watase's paper is an important one as the first dealing with 

 this species, but, being semi-popular in character and published 

 in Japanese, escaped notice for a considerable time and has only 

 lately received a little of the attention it deserves. Through the 

 kindness of Mr. Sotaro Matsushita, formerly of Redlands, 

 California, I have for some time been in possession of a translation, 

 and a very free transcription of some of its more interesting if 

 quaint passages should be neither inappropriate nor unwelcome 

 here. "Hotaru-ika, when seen externally, does not differ much 

 from other ika [squids]. Yet there are many interesting features 

 which we do not see in other ika. At each end of the two ' legs ' 

 there are three oblong, black spots. These small spots were 

 first discovered by the French scientist Joubin. Yet even he did 

 not know their function. According to the results of my own 

 study of these in living Japanese specimens, the spots were found 

 to produce a considerable light, penetrating to the space of about 



1 The "firefly squid" Watasenia scintillans (Berry). 



