Page:The history of silk, cotton, linen, wool, and other fibrous substances 2.djvu/143

 and consistent yellow ball; the laborer, of course, always remaining on the inside of the sphere which it is forming.

The silken filament, which when drawn out appears to be one thread, is composed of two fibres, unwound through the two orifices before described; and these fibres are brought together by means of two hooks, placed within the silk-worm's mouth for the purpose. The worm rests on its lower extremity throughout the unwinding operation, and employs its mouth and front legs in the task of directing and uniting the two filaments. The filament is not wound in regular concentric circles round the interior surface of the ball, but in spots, going backwards and forwards with a sort of wavy motion. This apparently irregular manner of proceeding is plainly perceptible when the silk is being reeled off the ball; which does not make more than one or two entire revolutions while ten or twelve yards of silk are being transferred to the reel.

At the end of the third or fourth day, the worm will have completed its task; and we have then a silk cocoon (See Figure 3. plate III.), with the worm imprisoned in its centre; the