84 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
and its disappearance at dawn, are characterised by the same changes in a 
reversed order in the two cases. Before the appearance of spontaneous: 
phosphorescence at night, and after its disappearance in the morning, 
there is a period of minimal excitability of about half an hour during 
which stirring still calls out phosphorescence. After this the organisms 
become completely refractory. 
15. Addition of fresh water, or formol, produces, during the period 
in which the organism is dying, a most vivid phosphorescence, which lasts 
from two to three minutes, and then fades and disappears. 3 
This display is very feeble during a daylight period, compared to what — 
is seen after dark when spontaneous phosphorescence is present. 
