In historical times the actual slaying of the victim was done by subordinates, _popae_, _victimarii_, etc.; but there is no doubt whatever that it was originally the work of the priest, for he seems at all times to have used one gesture which is clearly symbolic of it,[358] and there are traces also of a practice of wearing the toga in such a way as to leave the right arm free for the act.[359] That toga, or any other special robe worn by the priest, was always in whole or part red or purple. The purple-edged _toga praetexta_ was worn both by priests and magistrates, and by children under age; and I think there is good reason to believe that in all these cases the original idea was the same--that they took part, directly or indirectly, as primary or secondary agents in sacrificial acts. The Salii and the augurs wore the _trabea_, which was of purple or red, or both; the flamines had a special robe about the colour of which we are not informed, but the Flaminica Dialis wore a purple garment called _rica_, and a red veil called _flammeum_, which was also worn by the bride in the religious ceremony of marriage. Whether we are to see in this prevalence of red or purple any symbolism of the shedding of blood in sacrifice I cannot be sure, but the inference is a tempting one, and has been put forward with confidence by some recent investigators. It is worth noting that the Vestals, who did not sacrifice animals, wore white only.[360] If the red colour has anything to do with blood-shedding, it is probably more than merely symbolic; it may mean that the sacrificing priest partakes of that life and strength which he passes on to the god through the blood, that is the life, of the victim.[361] The Roman priests had also other insignia, of which the original meaning is less evident. The Flamen Dialis, and probably all the flamines, wore a cap with an olive-twig fastened to the top of it; this is well shown in the sculptures of the Ara Pacis of Augustus.[362] The flaminicae had a head-dress called _tutulus_, which consisted in part, at least, of a purple fillet or ribbon. The flamines, when actually sacrificing, wore a _galerus_, or hood of some kind made of the skin of a victim, and the Flamen Dialis in particular wore one made of the skin of a white heifer sacrificed to Jupiter.[363] In these various ways all priests were outwardly shown to be holy men, _sacerdotes_, marked off from the _profanum vulgus_. Only for the pontifices we have no information as to a special dress, just as we also have none as to their inauguratio.[364]