768 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [16] 
edges of the valves. These mollusks have two very powerful adductor 
muscles and are furnished with a foot or thick and fleshy prolongation 
of the central portion of the body, which can be protruded from the shell 
at the will of the animal. From the foot posteriorly arises the byssus, a 
small buneh of hair-like stiff threads, secreted by a gland, and by means 
of which the animal is permanently attached to some solid body, such 
as a rock, shell, bit of wood, &c. The gills, differing from those of the 
oyster, are made up of two lamine fixed to one end of the ventral mass 
along either side and free at the other, which is prolonged from either 
side of the posterior adductor muscle. 
The mussels are hermaphrodite like the oyster, and reproduce in the 
same manner (?), giving birth, after an incubation in the folds of the 
mantle, toa gelatinous mass, composed of a great number of young mus- 
sels, each furnished with its byssus and ready. to float away in the water, 
to become fixed to the first solid body which it encounters, or to perish in 
the mud, or serve as food for its innumerable enemies. Mussels can- 
not move about, or at the most move very slightly, yet, nevertheless, if a 
mussel becomes detached from its support by the rupture of its byssus it 
can move some by thrusting its foot.out from between the valves of the 
shell and pushing against the ground as against a fixed point. Mussels 
live nearly everywhere; there is not a point upon the coast of France 
where they cannot be met with, clustered in groups upon the rocks, in 
crevices, upon piles, and upon bits of submerged wood. They are to be 
found especially at the mouths of rivers and in muddy bays, the contact of 
fresh water not being objectionable to them, and, according to Beudant, 
they can even be acclimated out of sea-water. Of the many species of 
mussels, we shall speak here only of the edible one (Mytilus edulis), which 
has an oblong shell, of a very deep violet color externally, and white 
within except along the border and at the two muscular impressions, 
where the violet color also appears. 
In Normandy the light-colored mussel is much esteemed; it is smaller 
than the above and the valves are of a brown-fawn color. It is found 
principally at Villerville (Calvados). 
In France the mussel is taken throughout the entire year, except 
during the hottest months and the spawning season. The women and 
children, armed with a strong knife, gather them from the rocks which 
are uncovered at low tide, or dig them from the mud of the sea-shore. 
These mussels, however, are small, tough, and bitter, while those which 
grow in quiet and protected places, where the bottom is muddy but not 
sufficiently so to bury them, attain a large size and a delicate flavor. 
The mussel banks are practically inexhaustible, but as this mollusk is 
not of great value until it has attained a certain size, and lost the bit- 
terness and toughness belonging to the sea-mussel, the means of bring- 
ing it to perfection have long been sought for. Upon certain parts of 
our coast they are placed in parks like oysters, and in the Bay of 
Aiguillon they are made the object of a very important enterprise, which, 
