The numerous works and essays published by Lassen during half a century of unremitting labour, cover a wide field of Oriental research, and afford ample evidence of the thorough accuracy of his scholarship and the comprehensiveness of his learning. In 1829-31 he brought out, in conjunction with Schlegel, a critical annotated edition of the Hitopαdesα, the now well-known manual of political ethics in the form of fables, interspersed with moral maxims. The appearance of this edition marks the starting-point of the critical study of the Sanskrit literature. At the same time Lassen assisted his teacher and friend in editing and translating the first two cantos of the epic Râmâyana (1829-38). In 1832 he brought out the text of the first act of Bhavabhûti’s drama, Mâlatîrnâdhava, and a complete edition, with a Latin translation, of the Sânkhya-kârikâ, one of the chief works of the Sânkhya philosophy. In 1837 followed his edition and translation of Jayadeva’s charming lyrical drama, Gitagovinda, and his Institutiones linguae Pracritieae, which still forms the standard work on the popular dialects of the Indian dramas. His Anthologia Sanscritica, which came out the following year, contained several hitherto unpublished texts, and did much to stimulate the study of Sanskrit in German universities, where, indeed, it continues to be used, new editions of it having been published by Gildemeister in 1865 and 1868. In 1845 Lassen brought out a new and improved edition of Schlegel’s text and translation of the famous philosophical episode ofthe Mahdbhdrata, the “Bhagavadgîtâ.” He did not, however, confine himself to the study of Indian languages, but acted likewise as a scientific pioneer in other fields of philological inquiry. In his Beiträge zur Deutung der Eugubinischen Tafeln (1833), he prepared the way for the correct interpretation of the Umbrian inscriptions; and the Zeitschrift fur die Kunde des Morgenlandes (7 vols., 1837-50), started and conducted by him,— the first three volumes in conjunction with Ewald and Rodiger,— contains, among other valuable papers from his pen, grammatical sketches of the Beluchi and Brahui languages, and an essay on the Lycian inscriptions. Soon after the appearance of Burnouf’s Commentaire sur le Yaçna (1833), Lassen also directed his attention to the Zend, and to Iranian studies generally; and in his work Die altpersischen Keilinschriften von Persepolis (1836) he first made known the true character of the Old Persian cuneiform inscriptions, thereby anticipating, by one month, Bumoufs Mémoire on the same subject, while Major (Sir Henry) Rawlinson’s famous memoir on the Behistun inscription, though drawn up in Persia, independently of contemporaneous European research, at about the same time, did not reach the Royal Asiatic Society until three years later. Subsequently Lassen published, in the sixth volume of his journal (1845), a complete collection of all the Old Persian cuneiform inscriptions known up to that date. He also was the first scholar in Europe who took up, with signal success, the decipherment of the newly-discovered Bactrian coins, which furnished him the materials for his important essay, Zur Geschichte der griechischen und indo-scylhischen Könige in Baktrien, Kabul, und Indien (1838). He likewise contemplated bringing out a critical edition of the Vendidad; but, after publishing the first five fargards (1852), he felt that his whole energies were required for the successful accomplishment of the great undertaking of his life, with which his name will always be inseparably connected—his Indische Alterthumskunde. In this work—completed in four volumes, published respectively in 1847 (2d ed., 1867), 1849 (2d ed., 1874), 1858, and 1861—which forms one of the greatest monuments of untiring industry and critical scholarship, everything that could be gathered from native and foreign sources, relative to the political, social, and intellectual development of India, from the earliest times down to Mohammedan invasion, was worked up by him into a connected historical account. Only those acquainted with Indian history and literature, where nothing is fixed, can realize the enormous difficulty of the task; but in spite of much that may turn out to be erroneous, and in spite of still more that is, and from the nature of the subject must always be, uncertain and hypothetical, there can be no doubt that Lassen has laid in this work a solid foundation for future Indian historical and antiquarian research.