[63] OYSTER CULTURE. 815 
nothing for us to say in addition to the preceding description. But the 
emergent mud-flats are not the only ones upon which the rearing of mus- 
sels can be successfully undertaken. As a rule, this ought to be accom- 
plished upon all bottoms and in all basins, whether natural or artificial, 
where the deposit of mud renders the cultivation of oysters impossible, 
and it is not only possible but advantageous to combine the two methods 
or kinds of culture, especially when the rearing of oysters is carried 
on in the elaires described in a preceding chapter. This would be an 
excellent method of utilizing the stagnant basins, in which the water 
from the sea frees itself of sediment before being admitted to the claires, 
and which as a result of this use are necessarily muddy. In these basins, 
and in all of those which are dug for the purpose of rearing mussels, 
the hurdles would not be exposed, as in the bay of Aiguillon, to the 
fierce action of the sea and to the thousand other conditions which de- 
mand attention. Hence it would no longer be necessary to arrange 
them in the form of the traditional V, but they might be placed in par- 
allel lines according to the shape of the basin, leaving between each 
two rows sufficient space to pass in working them. <A gateway in the 
basin would permit the regulation of the height and the renewal of the 
water at pleasure, or allow it to run dry when necessary to aid in work- 
ing the hurdles. By combining this culture, with that of the oyster, the 
breeders could more than cover the expense, always considerable, of 
digging a basin for purifying the water and a canal to lead this water 
to the basins, an expense which the breeders with reason often shrink 
from, yet which ought to be considered indispensable to complete the 
breeding arrangements. In case the two kinds of cultivation are united, 
that of oysters in the claires and that of mussels in the purifying basin 
and entrance canal, the only precaution to be taken, to avoid injury 
to the first by the second, will be at the spawning time of the mussels 
to avoid using the water from the outer basin to supply the claires, 
for in such a case the claires would become filled with great numbers of 
mussel-germs, which would thus tend to supplant the oysters. This re- 
sult can be easily obviated by arranging upon the sides and outside the 
basin of purification a small body of water communicating upon one 
side by a gate with the entrance canal, before its entrance into the basin 
of the mussels, and upon the other with a claire, which, during a certain 
period, can play the réle of basin of purification. (See explanation to 
Fig. 18, page 54.) 
In Fig. 18, the purifying basin surrounds the claires and each one 
communicates with it by a sluice and gate. If it is desired to raise 
mussels in this basin, these gates can be placed between the canal and 
the basin and between the canal and one of the claires, so that with the 
gates of the basin closed the claire can be used as a basin of purifica- 
tion for the time being, and the spawn from the mussels prevented from 
entering where the oysters are. This arrangement will be necessary 
only during the spawning period of the mussels, that is, from the end of 
