954 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [12] 
subject to more or less disturbance; and if gravelly, it is certain to be 
the scene of much commotion in stormy weather. 
The first condition to be sought for, as favorable to oyster culture upon 
a coast, is one of rest. However rich the bottom of a region may be in 
the elements essential to the oyster, it cannot serve for the breeding of 
oysters if it is not a quiet one. Consequently, to mark out on a chart 
of Morbihan the regions covered with mud, would be to indicate the 
bottoms where oysters can be cultivated, and, without visiting the re- 
gion, one is able to affirm, by reference to the chart contained in this 
volume, that oyster culture is only possible in the Scorff, the Blavet 
the bay of Gavres, the river Saint-Philibert, the river Auray in the gulf 
of Morbihan, the estuary of Pénerf, and the entrance to the Vilaine. 
It is precisely at these places that the oyster-culturists have located. 
Oyster culture cannot be carried on at the entrance to the river Etel, 
about the peninsula of Quiberon, and in the many bays possessed by the 
islands Groix, Belle-Ile, Houat, and Heedick. 
It may be objected, with reference to our own statements above, that 
if the mud collects in sheltered situations it will cause an elevation of 
the bottom, against which the culturist of Morbihan will have to con- 
tend. An equilibrium is, however, finally established, and this fact is 
ot so much importance to culturists as to warrant mention here. It ap- 
pears as though, during the geological changes which resulted in our 
present coast line, the mouths of our rivers were given a size, quite ont 
of proportion to the importance of the rivers. The Scorff and the Bla- 
vet, both humble rivers, unite majestically in the roadstead of Lorient, 
whose great depth caused it to be chesen as the great central station of 
the India Company, and more recently as a naval station. Ten kilo- 
meters from their mouths, these rivers lose their importance, from their 
small size, and farther up, the Scorff especially, dashes through narrow 
granitic valleys and becomes the haunt of trout. These two streams 
play no part in the role of rivers, so to speak, while at their mouths all 
the conditions are strictly marine. The valleys through which they flow, 
in the interior, give rise to no alluvium for them to carry down, and the 
only phenomena observable are those produced by the sea. 
As we have stated before, the water enters the broad mouths of rivers, 
charged with mud, and, if it encounters perfect stillness there, the mud 
sinks and the bottom is gradually built up; but this elevation of the 
bottom has a limit. An equilibrium has already been established be- 
tween the tendency tobuild up the bottom and the wearing action of the 
tidal currents, and at present both the landward and the seaward cur- 
rents go, charged with mud, without producing any change in the level 
of the bottom. Two equal and opposing currents are thus represented 
as annulling each others actions. 
We insist upon this point, because of its important bearing upon oys- 
ter culture, and the breeding of oysters in particular. A state of equi- 
librium having been established with regard to the beds of our rivers, 
