XII 
SEA-MEADOWS 
1 
XPLORERS of the sea have described “ float- 
ing meadows,” consisting of countless 
millions of minute or microscopic plants, extending 
for, perhaps, a hundred miles without interruption. 
These simple plants, and the minute single-celled 
animals often associated with them, afford food for 
Crustaceans and other small fry, which, in turn, are 
eaten in great numbers by dainty feeders like 
mackerel. A few fishes, such as sardines, feed in 
great part directly on unicellulars. There is no 
doubt that the minute inhabitants of the superficial 
waters are directly or indirectly of great importance 
as food for creatures of larger growth, such as 
mackerel and herring, which, in turn, mean much 
to man. Dissolved organic compounds, sometimes 
rising from the floor of the sea, sometimes produced 
near the surface, may be utilized by larger animals 
(to what extent we do not yet know), or may be 
reclaimed for utilization by the varied and often 
subtle agencies of bacteria. So much, in passing, 
for the surface population; but what of the food- 
supply along the floor of the sea? 
In answering this question it has been usual, as 
we have seen in the preceding study, to give promi- 
88 
