30 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
of which persisted brilliantly for about three minutes, and then faded 
out. 
The weed (Polysiphonia nigrescens) was kept in the dark from the 
Thursday (September 24th) till Wednesday (September 30th), showing 
phosphorescence at night and none during the day. Fearing that it would 
decompose, it was then placed in ordinary diffuse daylight in a vessel 
with running sea-water. This treatment increased the amount of 
phosphorescence enormously, and in a day or two it was quite as 
phosphorescent as at first. Taken from the diffuse daylight to the dark 
room for examination, it was never phosphorescent, but at night it always 
phosphoresced most brilliantly. It, also, at the end, was fixed in 5 per 
cent. formol, and in this process ht up about twenty seconds after the 
application of the formol, and shone vividly for about three minutes before | 
dying out. | 
The examination of the united tow-nettings was difficult on account of 
the majority of the organisms being dead and in a broken-up condition — 
through the long duration of the experiment, but the following account 
was kindly given me by Mr. A. Scott, to whom my best thanks are | 
due : — 
Diatoms.—Biddulphia mobiliensis, 1,000; Chaetoceros densum, 40; 
Coscinodiscus radiatus, 50; Trochisca sp., 250. 
Corerops.—Calanus helgolandicus, 20; Pseudocalanus elongatus, 680; 
Temora longicornis, 100; Centropages hamatus, 10; 
Paracalanus parvus, 100; Lstas clavipes, 100; Copepod 
nauplii, 100; Copepod Juv., 200. 
Mo tuusca (larval)._-Gasteropods, 150; Lamellibranchs, 500. 
No Noctilucae were present. 
It is not probable that the diatoms or molluscan larvae were 
phosphorescent, so that there is little doubt that the phosphorescence was 
due to the copepods present, or certain species of these. 
