. Insect architecture. Insects. SPINNING CATERPILLARS. 311. Labium, or Imvtr lip of Cassus.—a, silk-tube. are like a pair of distaffs for spinning the gum into a silken thread. She fixes the first drop of°gum that issues where she pleases, and then draws back her head, or lets herself fall, while the gum, continuing to flow, is drawn out and lengthened into a double stream. Upon being exposed to the air, it imme- diately loses its fluidity, becomes dry, and acquires consistence and strength. She is never deceived in adjusting the dimensions of the [united] apertures, or in calculating the prop
. Insect architecture. Insects. SPINNING CATERPILLARS. 311. Labium, or Imvtr lip of Cassus.—a, silk-tube. are like a pair of distaffs for spinning the gum into a silken thread. She fixes the first drop of°gum that issues where she pleases, and then draws back her head, or lets herself fall, while the gum, continuing to flow, is drawn out and lengthened into a double stream. Upon being exposed to the air, it imme- diately loses its fluidity, becomes dry, and acquires consistence and strength. She is never deceived in adjusting the dimensions of the [united] apertures, or in calculating the proper thickness of the thread' but invariably makes the strength of it proportion- able to the weight of her body. " It would be a very curious thing to know how the gum which composes the silk is separated and drawn off from the other juices that nourish the animal. It must be accomplished like the secretions formed by glands in the human body. I am there- fore persuaded that the gum-bags of the silk-worm are furnished with a set of minute glands, which, being impregnated with gum, afford a free passage to all the juices of the mulberry-leaf corresponding. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Rennie, James, 1787-1867. London, M. A. Nattali
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectinsects, bookyear1846
