First part of L. Trouvelot's article on native North American silk-producing moths, published in the first issue of the American Naturalist (1867). It surveys eight or ten American species and judges which could yield usable silk, concluding that only Telea Polyphemus is practical. Trouvelot recounts his efforts since 1860 to raise the Polyphemus worm, then describes the moth's natural history: emergence from the cocoon, wing development, egg-laying, hatching and moulting. The text breaks off with 'To be continued'.