instruments like those that have been employed in Saxony and Bavaria. In the former country a thin, flat iron tool with a
bent end is inserted in the shell. The handle is then turned to go°, and
the shell is opened without injury to the animal. (See Fig. io.)
Another implement is a pair of pliers with sharp-pointed jaws and a
screw between the arms, which is turned by the hand until the valves of
the shell are sufficiently distended to see whether it contains a
pearl. (See Fig. ii.) If
it does not, the animal is returned to its former haunts, perhaps to
propagate more valuable progeny. This wholesale destruction, together
with the depredations of hogs, which have exterminated whole shoals of
Unios when the brooks were low, and the elements introduced into the
water by manufacturing industries, have no doubt exhausted many
varieties of these shells. The more eastern States are so densely
