Resuming then the results we have reached, it appears that Scot had met with this Arabic commentary on the Natural History of Aristotle while he was still in Sicily, and had made extracts from it for his _Physionomia_. Coming to Spain he probably carried the manuscript with him, and as his version of the _De Animalibus ad Caesarem_ seems to have been the first complete translation he made from the Arabic, and to have been published shortly after he came to the Castiles, he may possibly have begun work upon it even before his arrival there. On every account, there being no positive evidence to the contrary, we may conjecture that the _De Animalibus ad Caesarem_, like the _Physionomia_, belongs to the year 1209. If the latter work appeared at Palermo in time for the royal marriage, which took place in spring, the former may well have been completed and published towards the end of the same year, when Scot had no doubt been already some time settled in Toledo. The second form in which Michael Scot produced his work upon the Natural History of Aristotle was that of a version called the _Abbreviatio Avicennae_. The full title as it appears in the printed copy[87] is: ‘Avicenna de Animalibus per Magistrum Michaelem Scotum de Arabico in Latinum translatus.’ Like the _De Animalibus ad Caesarem_ it consists of nineteen books, thus comprehending the three Aristotelic treatises in one work. The name of _Ibn Sina_ or Avicenna, the author of the Arabic original, is significant, as it enables us to connect in a remarkable way the present labours of Scot’s pen with those which had in a past age proceeded from the school of translators at Toledo, and to place the _Abbreviatio_ in its true relation with the system of versions which had been published there nearly a century before. We have already remarked that Don Raymon directed the attention of his translators to Avicenna as the best representative, both of Aristotle himself and of the Arabian wisdom which had gathered about his writings. A manuscript of great interest preserved in the library of the Vatican[88] shows what the labours of Gundisalvus, Avendeath, and their coadjutors had been, and how far they had proceeded in the task of making this author accessible to Latin students. From it we learn that the _Logic_, the _Physics_, the _De Cœlo et Mundo_, the _Metaphysics_; the _De Anima_, called also _Liber sextus de Naturalibus_; and the _De generatione Lapidum_ of Avicenna, had come from the school of Toledo during the twelfth century in a Latin dress. The last-named treatise was apparently a comment on the _Meteora_ of Aristotle, and the whole belonged to that _Kitab Alchefâ_, which was called by the Latins the _Assephae_, _Asschiphe_ or _Liber Sufficientiae_. This collection was said to form but the first and most common of the three bodies of philosophy composed by Avicenna. It represented the teaching of Aristotle and the Peripatetics, while the