III. _The Dalmatica._—We have already entered at length into the history of this word and of the vestment to which it was applied. It does not seem to have differed essentially from the _alba_; but it appears that two[44] vestments were worn at Rome, an _alba_ and a _dalmatica_, though it is evident from the Toletan canons and other sources that at this early period such was not the case elsewhere. In early pictures the two vestments are rarely represented side by side; it is probable that the _dalmatica_ was so long as to conceal the _alba_, just as the dalmatic on mediaeval effigies of Bishops often hides the tunicle. It seems, however, to have been shown on the ancient picture of Gregory the Great, described by Joannes Diaconus; and we find that Gregory granted its use to Bishop Aregius of Gap and to his Archdeacon (Ep. ix 107: Migne, lxxvii 1033), forwarding the vestments at the same time as the letter. Clearly the Pope does not denote the _alba_ by the word _dalmatica_, as we have seen St Isidore of Seville do, for Aregius would naturally wear an _alba_ without papal interference. The vestment in question must, therefore, have been another, resembling the alb in outline, but only worn either at Rome or by those on whom the Pope saw fit to confer it. The history of the spread of the _dalmatica_ must have been similar to that of the _mappula_. By the time the third period begins we find it established as an independent vestment, differing from its parent, the _alba_, in one important respect, which will be detailed in the following chapter.