The silkworm, when ready to make its cocoon, seeks a suitable support. This is usually found among the twigs of brush placed for the purpose over the trays in which the worms have been grown. At first the worm proceeds by stretching filaments backward and forward from one twig to another in such manner as to include a space large enough for the future cocoon. When sufficient support has thus been obtained, the worm incloses itself in a layer of filaments adhering to the support and following the shape of the new cocoon, of which it forms the outermost stratum. After having thus provided a support and outlined the cocoon, the worm begins the serious work of constrution. The filament from its silk receiver issues from two small spinnarets situated near its jaws. Each filament, as it comes out, is coated with a layer of exceedingly tenacious natural gum, and they at once unite to form a single flattened thread, the two parts lying side by side. It is this flat thread, called the "baye" or "brin," which serves as the material for making the cocoon, and which, when subsequently unwound, is the filament used in making up the raw silk. While spinning, the worm moves its head continually from right to left, laying on the filament in a succession of lines somewhat resembling the shape of the figure eight. As the worm continues the work of making its cocoon, the filament expressed from its body in the manner described is deposited in nearly even layers all over the interior of the wall of the cocoon, which gradually becomes thicker and harder. The filament issuing from the spinnarets is immediately attached to that already in place by means of the gum which has been mentioned. When the store of silk in the body of the worm is exhausted, the cocoon is finished, and the worm, once more shedding its skin, becomes dormant and begins to undergo its change into a moth. It is at this point that its labors in the production of silk terminate and those of man begin. A certain number of the cocoons are set aside for reproduction.