these renderings into Arabic, however, have been preserved in the
original and sometimes in paraphrase. Unusually important was the
translation of the book called the _Khuday Nameh,_ the value of which
has long been appreciated by science. Questions of vital importance in
connection with this history are its relation to the _Shah Nameh_ and
the examination of its various translations in the Musalman period. The
loss of this book, perhaps the most important monument of Middle Persian
literature, is to be particularly deplored in that with it has perished
the connecting link of the historical evolution of Iran, incorporating
the religious and clerical legislature in an official redaction. Of
capital importance also was another book called the Ain Nameh[1] or the
Book of Institutes, a valuable source of the internal history of the
Sasanian Empire, comprising a descriptive table of official dignitaries
or the _Gah Nameh._[2] Judging by the clue given in the Fihrist (118,28)
it would appear that the _Book of Taj_ also was a historical one since
it has been explained that the book treated of the "Acts of Anushirwan."
As a matter of fact, among the books written by the Persians on epic and
historical subjects and indexed in the same Fihrist (305, 8-13) has been
mentioned the _Book of Taj._[3]

[Footnote 1: See below and also my book on _The Materials from Arabic
sources,_ &c., 63-66. Like Masudi in his _Kitab_ at Tambih, Asadi in
his _Lughal al-Furs_ (Asadi's _neupersischen Worterbuch Lughat al-Furs,_
edited by P. Horn, 1897, 110, 1), identifies the word _ain_ with the
word _rasam,_ practice or custom. As regards the word _ain_ in the
Iranian languages see Horn _Grundriss der neu persischen Etymologie_,
15-16; Hubschmann, _Persische Studien_ 11, and B.G.A. IV, 175, and VIII,
Glossarium IX. To understand the ancient usage of the term the modern
Parsi expression _Dad wa ain din_ in the sense of religious law and
custom helps us. In this phrase the word _dad_ corresponds to the modern