More than 140 years have gone by since R. Hercher's 1864 Teubner edition, a book with serious editorial shortcomings which have been often underlined in recent publications. This new text offers an accurate and new critical edition as a result of an extensive and detailed work undertook by a team of scholars of the University of Oviedo (Spain), under the direction of the Professor Manuela García Valdés. The text has been established on the basis of a complete collation of all the most significant manuscripts of Aelians' textual tradition. This is the first edition with an accurate and scientific critical apparatus by applying the scope of textual criticism and ecdotics. The edition also takes into account the literary koiné of II-III centuries AD and the authors' own style. This edition offers to all scholars a reliable text as a starting point for future research on Aelians' Language and Stoic thought. It will be also useful for studies on zoology, on animals' habits and behaviour, medieval bestiaries, and on the concepts of Science and Technique in Late Antiquity. Confronted with his wealth of materials, the author writes each chapter as a finished unit, as a short story. He uses a wide variety of both literary and linguistic expedients, resorting to formal and content resources.