188 DR W. B. DRUMMOND ON 
ployed in capturing cod, of which 75,000,000 were said to be 
taken. Off Newfoundland myriads of cod have been 
captured annually for three hundred years without the 
numbers seeming to diminish. 
These figures may be taken as a sample to indicate some- 
thing of the abundance of a few well-known species in a 
small area of the ocean. What are we to say of the lower 
and smaller forms of life on which these to a great extent 
depend for food. Let me speak of two phenomena which 
illustrate the abundance of minute forms. 
The first is the so-called Milky Sea (Mer de Lait), which 
has often been observed by sailors in the Indian Ocean. 
The sea is described as appearing during the night of a 
milky-white colour, or as resembling a vast snowfield seen 
by the light of the moon. If a bucket of water is drawn 
up it is found to contain hundreds of minute luminous 
bodies, which shine more brightly when shaken up. The 
sea loses its milky appearance during the day, but the 
phenomenon reappears at night. This milky sea may 
continue for 600 or 700 miles. 
Allied to this is the beautiful phosphorescence often to be 
seen round our own coasts. Off the west coast of Scotland 
on a warm summer evening, one can often see the wake of 
the boat glowing with a golden yellow light far behind, 
while the water drips from the oars in a golden stream. 
In warmer latitudes the phosphorescence may be so brilliant 
that some writers speak of having been able to read by the 
light given off from the wake of a ship. This phosphor- 
escence is known to be due to innumerable minute organisms, 
and it is an interesting fact that almost all the forms of 
life which float about as Plankton are luminous, and emit 
light when stimulated. What particular benefit is derived 
from the photogenic power is doubtful, nor is much known 
as to the chemistry of light-production. One thing seems 
certain, that it has nothing to do with phosphorus. Phos- 
phorus and its photogenic compounds are poisonous sub- 
stances, and incompatible with cell life. Animal phosphor- 
escence is, however, always associated with the absorption of 
oxygen, and hence must be regarded, like the shining of 
phosphorus itself, as due to slow combustion (oxidation) 
