Notes on the Locusta septentrionalis americanae decem septima / by Nathaniel Potter.

  • Potter, Nathaniel, 1770-1843.
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Notes on the Locusta septentrionalis americanae decem septima / by Nathaniel Potter. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    shell, dark brown and elastic, but more brittle, and bent to a cer- tain extent, fractures short, like a pipe stem. The edges and points of the side pieces are serrated, jorming perfect saws, while their flat- tened surfaces form rasps equally perfect. When the instrument is protruded and examined by the microscope, the denticulations of Ihe saws are clearly perceived. There are fijteen teeth on each side, symmetrically arranged, tapering away in fineness towards the point, where we find three or four more, so small that it is scarcely possible to determine, by the best glasses, whether there are three or four. In some there appeared to be three, in others four. Previous to the application of the instruments, the female de- posites a fluid on the part to be operated on. It seems to be in- tended as an emollient, and probably to mark the extent of her work. It is a secretion from the inner surface of the oviduct, so exquisitely fine that it is only to be seen by a fine glass. The prac- tice of softening the place of deposite for eggs is not uncommon among insects and amphibious animals. Some of the tortoises use their urine to soften the surface of the ground, that they may ex- cavate the hard soil with more ease, and deposite their eggs quicker. When the female selects a limb, she goes formally and indus- triously to work, and soon finishes it. She raises her body, ex- tends the point of the instrument, and with her whole weight pierces the bark with the upper point of the centre piece or chisel, which is like the flattened point of a thumb lancet, making way for the side pieces or saws. Though the puncture is very minute, scarcely perceptible, it is sufficient for a place of entry, and a quick sawing motion now commences, and continues till the apertures are large enough to admit the other side piece, which follows with the like motion. As soon as the blade point is fairly inserted, say the twelfth of an inch, she presses on the part attached to her body, and then, by a lever, raises the ends of the divided fibre; she then adjusts the three different parts of the instrument, forming two saws by Us edges, two rasps by its flattened sides, and a perforator or chisel by Us point. The uses of the perforator and saws are easily per-