29 
swim at various depths, their danger from accidents and ene- 
mies is greatly diminished, and their chance of reaching 
maturity increases hundreds, and probably thousands of times.. 
My experiments show that there is no difficulty in develop- 
ing them up to this point in the house in small aquaria, and 
in carrying them safely past the most precarious part of their 
lives, and freeing them from all their greatest dangers. 
Although the mortality at these early stages is so excessive, 
the number of young which pass through them safely without 
help is very great, and if there were no other dangers and 
uncertainties there would be no need of measures for their 
protection. As they swim to and fro in the water, they are 
carried to great distances by the tides and currents and reach 
all parts of the region of water in which the parent bed is 
situated. In a favorable year a floating plank or bush, or 
piece of drift-wood, will be found to become covered with 
small oysters which have fastened to it, although it may not 
be within miles of any natural oyster bank. The fact that the 
young may be collected in this way in any part of the Chesa- 
peake Bay shows that the young oysters must settle down 
upon the bottom in nearly all parts of the bay, and we should 
expect the adults to have an equally general distribution. This, 
is far from the case, and nothing could be farther from the truth 
than the idea that the bottom of the waters of the oyster regions, 
is uniformly covered with oysters, and that it is only neces- 
sary to throw a dredge overboard and drag it along the bottom 
for a short distance, in order to bring it up full. Nothing 
could be a greater mistake, for both in this country and in 
Europe, the oysters are restricted to particular spots, “ beds n 
or “ banks,” which are as well defined and almost as sharply 
limited as the tracts of wood-land in a farming country. 
These beds are so w T ell marked that they can be laid down on 
a chart or staked out with buoys; and even in the best oyster 
regions they occupy such an inconsiderable part of the bottom 
that any one ignorant of their position would have very little 
chance of finding oysters by promiscuous dredging. Although 
the young are distributed every year, by the tides and currents, 
to all parts of the bottom, the dredge very seldom brings up, 
even a single oyster outside the limits of the beds. 
