704 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [22] 
rise of water of from 2 to 2.5 meters, as well as the great and powerful 
force of this water-mass. Beds thus laid down would cost much more 
than the ditched and planked ones of Arcachon. But even if they were 
so placed as to bid defiance to the most severe flood-storm, they would 
indeed hardly suffice to protect the breeding oysters from being covered 
with mud and sand; and thus one flood-storm, or storm in connection 
with a flood-tide, might destroy the accumulated oysters of many gener- 
ations. A visit made to the island of Norderney showed us how de- 
structive nature can be to the oyster-beds of our sea-flats. Upon the 
inner side of this island, early in the year 1869, a surface of 825 square 
meters was dug out, and made firm by double-planked walls to about 
the height of half tide. The space between the walls and banks was 
filled in with sand and mud, and the inclosure itself was divided into 
two compartments, one of which was longer than the other. 
In the smaller division the water was detained to enable it to deposit 
its coarser materials before it was allowed to pass into the larger one. 
In the beginning of June, 20,000 mature oysters were placed in these 
artificial beds, with the expectation of reaping a rich harvest of young 
oysters; but the harvest never came. Star-fish and crabs attacked the 
oysters, in the beginning of August flood-storms broke down the walls, 
and the storms of autumn completed the work of destruction, so that 
very soon nothing was left of the entire enterprise. If the situation of 
the free sea-flats is not suitable for the formation of oyster-beds, per- 
haps there is still a possibility of artificial oyster-breeding being carried 
on inside of the dikes which protect the fertile marsh-land along the Ger- 
man coast from the envroachments of the waters of the North Sea. For 
this purpose basins would have to be dug outinside of the dike and placed 
in connection with the sea by means of canals. Where these canals cut 
through the dike it would be necessary to build a gate, in order to pre- 
vent the sea-water from passing in during high-tide. Then, oyster-beds 
could not be laid down in the neighborhood of this gate, because it would 
serve not only as an inlet for salt water, but as an outlet for the fresh 
water from the marsh-land, and so fresh water instead of sea-water 
would cover the oyster-beds. But evenif it is admitted that oyster-beds 
might be laid down inside of a dike without danger to the diked lands, 
and with sluices and gates to permit the inflow of sea-water, there are 
yet several questions to be answered. How will oysters thrive in such 
beds? Will they receive enough nourishment to become fat? How will 
they exist during continued cold weather? And will they produce young 
in such a place? It is certain that they will not receive as much food 
as in the open sea, since they cannot have nearly as much water as will 
pass over them upon the natural beds; and the quantity of nourishment 
varies in proportion to the amount of water which passes over the beds. 
In these beds the oysters would also be in danger of being buried in the 
deep mud, and in order to prevent this they must either be changed 
very often into clean beds, or else a cleaning-pond must be formed beside 
