BY DR. OSCAR KATZ. 335 



more elaborate paper on this subject I am going to prepare for 

 a futui-e Meeting — I wish to call attention to this interesting 

 subject, as the question of the cause of certain kinds of phos- 

 phorescence of sea-water, for the explanation of which nothing 

 certain as yet has been advanced, will now, it is to be hoped, soon 

 be solved. Pf liiger (quoted from Dr. Fischer's Treatise, I.e., p. 55), 

 already suggested, a number of years ago, that micro-organisms of 

 the group Bacteria participate in the production of phosphorescence 

 of sea-water, and the experiments recently made by Fischer with 

 pure cultures of luminous schizomycetes on ordinary sea-water, 

 convinced him of the striking resemblance which an artificially 

 produced luminosity of sea-water bears to that magnificent 

 phenomenon described by English writers as " milky sea." The 

 direct proof, he says, that such an appearance is brought about by 

 bacteria of the above nature, is still a desideratum, but by means 

 of continued researches it is sure to succeed. For my part 

 I have not the least doubt that this will be the case, to judge from 

 what I have read and heard about "milky seas" — I have not yet 

 been fortunate enough to come across such a phenomenon — and 

 from experiments made by me on sea-water with pure cultures of 

 the three species of bacteria mentioned. A systematic or occasional 

 search for such like sea-water bacteria at different places of the 

 globe, may no doubt add to the number of kinds already found, 

 although I believe the number of them will not become very large. 

 Those forms which are now known belong to the aerobic class 

 of micro-organisms, that is to say, they neither grow nor emit light 

 without the presence of air (oxygen). Whether or not phosphores 

 cent bacteria of the anaerobic class, propagating only with the 

 exclusion of oxygen, may be detected in sea-water, either directly 

 or indirectly (in marine animals), and whether or not such micro- 

 organisms may play a part in certain kinds of phosphoresence of 

 sea-water, all this is still an open question. There is on record 

 the statement by two investigators, Bancel and Husson, (1) 



(1) Surla phosphorescence de la viande de homard. Comptes rendm, 1879, 

 Vol. 88, pp. 191-192. 



