8o 
M. SASAICI. 
animals are so weak that in carrying them from tlie sea to the aquarium 
they wasted and died. As they wasted, tlie luminousity in question be- 
came very feeble, and naturally with their expiration, the light of the 
luminous organs gradually vanished altogether. This being so, I then tried 
to observe the animals directly while they were swimming in the net. 
Ikit no good means were found easily to distinguish the sexes on such 
dark nights, even with the feeble light of the moon or of a lantern. 
However in my examinations at night, no special variety of the light 
could be found, the colour of the light being always the same. And in 
one case, putting in a vessel and observing about 30 specimens in a fish- 
ing boat while they were yet actively on motion, I verified the fact that 
their luminosity is uniform. In the morning, to my surprise, a male 
was found dead among those 30 specimens ; this proves that it had the 
same colour of light with the female on that night. The above data seem 
to prove the fact that the colour of the light of the luminous organs is the 
same in both sexes. 
Again, in late July of the same year, I made another observation on 
the phosphorescence under consideration and then it was quite evident to 
me that the luminosity of the brachial organ was at this season notice- 
ably feebler than in the spring. 
The phosphorescence of the immature animal can never be studied in 
Namerikawa, young ones thus far not being found there. 
3. Food. 
The contents of the stomachs were examined 4 times on the preserved 
specimens and they were as follows : 
i) Among 20 females caught with the Fiikubc-aiiii (see p. 91) on April 
25, were 4 specimens with some amount of silvery blackish substance like 
the iridocytes of fishes and some pieces of shells of small crustaceans, 
but the remaining 16 had nothing in the stomach. 
ii) In 20 females obtained with the same kind of net on April 27, the 
stomach was found to be quite empty. 
