14 NOCTILUCA MILIARIS. 



From the month of July to December, there is but slight 

 difficulty in procuring specimens for observation, and during these 

 months the sea has shown incessant alternations of luminosity 

 and darkness. These conditions, therefore, probably depend not 

 merely upon the presence or absence of the animal itself, but on 

 some peculiar conditions of its organism, or of the water acting 

 upon the animals. The buoyancy of the Noctiluca is such that it 

 rises to the surface of tranquil water without much effort, and 

 may easily be procured. When kept in a test tube they will 

 flourish for two or three weeks without the water being changed, 

 and if at the end of that term they die, it will most probably be 

 from some accidental cause rather than from the limitation of 

 space. If specimens be sent through the medium of the post, 

 the violent shaking thus occasioned is generally the cause of great 

 mortality amongst them. 



It was stated by a speaker at a meeting of the British Associa- 

 tion that the Noctiluca had occurred that year in such vast 

 numbers that the sea had become a beautiful rose colour, and 

 Captain Wilson Barber, commander of the T.S.S. Dacia, states 

 the following in a recent number of Science Gossip : — 



" I have just been up the Persian Gulf laying a cable, and 

 while we were proceeding from Jack up the Persian Gulf, we 

 encountered immense numbers of the minute phosphorescent 

 Noctiluca Afllla?-ls, the centre reddish speck of which caused the 

 water to appear in places as if covered with clotted blood. It was 

 of the most intensely red colour, appearing in streaks and blotches 

 all around. I caught quantities of it for examination. The water 

 in places, when fished up in a bucket, seemed one mass of them, 

 though in a small quantity they lost a good deal of their colour. 

 Mixed up with them were a few pieces of TrlchodesDilum 

 Ehrenbergli, but very little. There were also quantites of sea- 

 snakes and medusae. The sea was quite calm, and at night the 

 steamer stirred up the most brilliant green waves I ever saw."* 



Of the nature of the phosphorescence, Professor Allman states 

 the following : — " When transferred from the net to a jar of sea 

 water, the Noctiluca soon rise to the surface, where they habitually 



* The red speck to which the writer referred was simply the mass of 

 protoplasmic matter, clearly seen through the transparent body of the animal. 



