Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. As regards the text from which this translation has been made, it is based upon that of Stein''s critical edition (berlin, I 869-1 that is to say the estimate there made of the comparative value of the authorities has been on the whole accepted as a just one, rather than that which depreciates the value of the Medicean ms. And of the class to which it belongs. On the other hand the conjectural emendations proposed by Stein have very seldom been adopted, and his text has been departed from in a large number of other instances also, which will for the most part be found recorded in the notes.