The knowledge which Julius Caesar possessed of the Druids and of their literary system was very incomplete; yet he presents to his readers a truly grand spectacle, when he speaks of their numerous schools, frequented by an immense number of the youths of the country, so different from those of Rome, in which his own mind had been trained--"Ad has magnus adolescentium numerus disciplinae causa concurrit:" when he mentions the political and civil subjects submitted to the judgment of literary men--"de omnibus controversiis publicis privatisque constituunt. ... Si de hereditate, si de finibus controversia est, iidem decernunt:" when he states the length of their studies--"annos nonnulli vicenos in disciplina permanent:" when he finally draws a short sketch of their course of instruction-- "multa de sideribus atque eorum motu, de mundi ac terrarum magnitudine, .... disputant juventutique tradunt." But, unfortunately, the great author of the "Commentaries" had not sufficiently studied the social state of the Celts in Gaul and Britain; he never mentions the clan institution, even when he speaks of the feuds--factiones--which invariably split their septs--civitates--into hostile parties. In his eleventh chapter, when describing the contentions which were constantly rife in the cities, villages, even single houses, when remarking the continual shifting of the supreme authority from the Edui to the Sequani, and reciprocally, he seems to be giving in a few phrases the long history of the Irish Celts; yet he does not appear to be aware of the cause of this universal agitation, namely, the clan system, of which he does not say a single world. How could he have perceived the effect of that system on their literature and art? To understand it at once it suffices to describe in a few words the various branches of studies pursued by their learned men; and, as we are best acquainted with that portion of the subject which concerns Ireland, we will confine ourselves to it. There is no doubt the other agglomerations of Celtic tribes, the Gauls chiefly, enjoyed institutions very similar, if not perfectly alike. The highest generic name for a learned man or doctor was "ollamh." These ollamhs formed a kind of order in the race, and the privileges bestowed on them were most extensive. "Each one of them was allowed a standing income of twenty-one cows and their grasses," in the chieftain's territory, besides ample refections for himself and his attendants, to the number of twenty-four, including his subordinate tutors, his advanced pupils, and his retinue of servants. He was entitled to have two hounds and six horses, . . . and the privilege of conferring a temporary sanctuary from injury or arrest by carrying his wand, or having it carried around or over the person or place to be protected. His wife also enjoyed certain other valuable privileges.--(Prof. E. Curry, Lecture I.)