and placed in two parallel
rows upon the mantle or fleshy surface of the animal. A sufficient
number having been placed on one side, the operation is repeated on the
other. Stimulated by the irritating bodies, the suffering animal
spasmodically presses against both sides of its testaceous skeleton,
keeping the matrices in place. This being done, the mussels are
deposited one by one in canals, or streams or pools connected
therewith, five or six inches apart, at depths of from two to five
feet, in lots of from five to fifty thousand.
If
taken up in a few days after the introduction of the mould, they will
be found attached to the shell by a membraneous secretion, which at a
later period appears as if impregnated with calcareous matter, and
finally layers of nacre are deposited around each neucleus, the process
being analogous to the formation of calculary concretions in animals of
a higher development. A ridge of marl generally extends from one pearly
tumour to another, conÂnecting them all together.
About
six times in the course of the season, several tubs of night-soil are
thrown into the reservoir for the nourishment of the animals, Great
care is taken to prevent goat manure from falling in, as it is highly
detrimental to the mussels,
