At least two versions of the _De Animalibus_ appeared from the pen of Scot. These have sometimes been confounded with each other, but are really quite distinct, representing the labours of two different Arabian commentators on the text of Aristotle. We may best commence by examining that of which least is known, the _De Animalibus ad Caesarem_, as it is commonly called, and this the rather that there is good reason to suppose it represents the first Arabian work on Natural History which came into Scot’s hands. Nothing is known certainly regarding the author of this commentary. Jourdain and Steinschneider conclude with reason that the text must have been an Arabic and not a Hebrew one, as Camus[81] and Wüstenfeld[82] contend. No one, however, has hitherto ventured any suggestion throwing light on the personality of the writer. The colophon to the copy of Scot’s version in the _Bibliotheca Angelica_ of Rome contains the word _Alphagiri_, which would seem to stand for the proper name Al Faquir. But in all probability, as we shall presently show, this may be merely the name of the Spanish Jew who aided Michael Scot in the work of translation. The expression ‘secundum extractionem Michaelis Scoti,’ which is used in the same colophon, would seem to indicate that this version, voluminous as it is, was no more than a compend of the original. The title of the manuscript too: ‘Incipit flos primi libri Aristotelis de Animalibus’ agrees curiously with this, and with the word _Abbreviatio_ (_Avicennae_), used to describe Scot’s second version of the _De Animalibus_ of which we are presently to speak. Are we then to suppose that in each case the translator exercised his faculty of selection, and that the form of these compends was due, not to Avicenna, nor to the unknown author of the text called in Scot’s version the _De Animalibus ad Caesarem_, but to Scot himself? The expressions just cited would seem to open the way for such a conclusion.