1. Harley MS 866, ff 17r-33r Reference (shelfmark): Harley MS 866, ff 17r-33r Title: Alanus ab Insula (Alain de Lille), De planctu naturae. Scope & Content: Alain de Lille's De planctu naturae, an allegorical poem reflecting12th-century knowledge of natural sciences. Collection Area: Western Manuscripts Languages: Latin Date Range: c 1390-c 1410 Extent: 17 folios.