The author, B., had previously published for the same editor the first complete lemmatised index of Aristotle's De partibus animalium (1990) and De historia animalium (2004). This index verborum of Aristotle's De generatione animalium, as B. says in the general introduction (p. ix), is not the first one. As one knows, after his new edition of the Greek text of this treatise (1965), H.J. Drossaart-Lulofs had published in 1992 a Greek index as a supplement to the edition by A. van Oppenraaij of the Arabic–Latin translation by M. Scot of Aristotle's De animalibus (Books 15–19: Generation of animals). But B.'s index verborum brings something more. Like the other publications of the LASLA (‘Laboratory for the Statistical Analysis of Ancient Languages’) based in the University of Liège (Belgium), it gives not only statistical tables and frequency lists of the word lemmatised but also grammatical and lexical information. The book is divided into four unequal parts. The first and the main part (A, pp. 3–353) is devoted to the index verborum of De generatione animalium. Drossaart-Lulofs’s edition of the text obviously has been used to realise the index. It includes also frequency lists of the lemmas classified in different kinds of order. The second part (B, pp. 357–91) contains synoptical frequency lists of seven lexical categories (zoonyms, phytonyms, names of minerals and metals, toponyms and ethnical names, Greek months, theonyms and heroes’ names, anthroponyms) in the main three zoological Aristotelian treatises but also in De incessu animalium, De motu animalium and in the small treatises of the Parva naturalia. A Latin translation of the zoonyms is given. For instance, B. suggests that the unidentified trochos, whose name appears three times in Generation of animals Book 3 (757a3, 4, 6), is a sea animal such as a fish. In the third and fourth parts, B. gathers addenda to the index verborum of De partibus animalium and various corrigenda to De historia and De partibus animalium. No doubt, this book will be a useful instrument for the scientific study of Aristotle's Generation of animals and, more broadly, of the zoological and biological works of Aristotle.