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Page:Popular Science Monthly Volume 17.djvu/121

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CAPTURE AMONG THE MOLLUSKS.
111

the condition of the apparatus at every moment. Figs. 1 and 3 represent two of the reflectors. That shown in Fig. 1 is used to light up the mouth, and is of such power as to render the teeth transparent, and make them show every detail of their condition. Placed on the extremity of a probe inserted in the œsophagus, it makes it possible to observe the condition of the stomach. Fig. 3 shows the reflector with mirrors for use in laryngoscopy and rhinoscopy. This adaptation of the instrument may be used by dentists to show the back part of the teeth, without compelling the patient to assume a disagreeable position, as in Fig. 2. The polyscopes are superior to every other device for introducing light to all parts of the human body. With them the source of light may be placed at as minute a distance as is desired from the part to be examined without inconvenience to the operator. With a slight modification the polyscope may be employed as the instrument for performing the very different operation of cauterization. It is of service in other fields than those of medicine and surgery. Captain Manceron, at St. Thomas of Aquinas, has used it to examine the interior of shells and cannon. It is employed likewise in powder magazines, and is a similar apparatus to that used by divers and gatherers of oysters, corals, and pearls, to light up the bottom of the sea.

CAPTURE AMONG THE MOLLUSKS.

MR. STEPHEN CLOGG has kindly forwarded us a box containing a shanny and a mussel, which he describes as having been taken in the harbor at Looe, Cornwall, in exactly the position represented in the accompanying illustration. The shanny and mussel, our correspondent writes, were taken by a fisherman who was gathering mussels for bait at Looe. Mussels are found in great numbers at the bottom of the harbor there, and the fishermen use a long-handled, four-pronged fork for catching them. A boat is moored over the spot on which the mussels are to be found, and the fork is employed to bring them from below into the boat. In the case in question, our correspondent assures us the shanny and mussel were brought up as shown in our illustration. The fish was alive when taken, and its head firmly fixed in the mussel. This certainly may be considered a curious capture, and from the evidence it may be fairly assumed that the shanny, seeing a tempting mussel with its mouth open, was induced to pop his head in—an operation which Master Mussel doubtless resented by immediately closing its valves, retaining the fish in its deadly grasp. A case in point of fish being taken in this way is mentioned by Couch, in which Lacépède records an instance where, as he (Lacépède) supposes, a shanny had made an attempt to feed on an oyster