Stock Photo - Metamorphosis of a silkworm, from young caterpillar, shedding skin, spinning silk cocoon, chrysalis stage, and emergence as moth. Handcoloured copperplate engraving from Bertuch's Bilderbuch fur Kinder (Picture Book for Children), Weimar, 1792. Friedrich Johann Bertuch (1747-1822) was a German publisher and man of arts most famous for his 12-volume encyclopedia for children illustrated with 1,200 engraved plates on natural history, science, costume, mythology, etc., published from 1790-1830. Metamorphosis of a silkworm, from young caterpillar, shedding skin, spinning silk cocoon, chrysalis stage, and emergence as moth. Handcoloured copperplate engraving from Bertuch's 'Bilderbuch fur Kinder' (Picture Book for Children), Weimar, 1792. Friedrich Johann Bertuch (1747-1822) was a German publisher and man of arts most famous for his 12-volume encyclopedia for children illustrated with 1,200 engraved plates on natural history, science, costume, mythology, etc., published from 1790-1830.