of the two communities, when they were about to be amalgamated, may be conceived to have been substantially similar; and in solving the problem of union they would have to choose between the alternatives of retaining duplicate institutions or of abolishing one set of these and extending the other to the whole united community.  They adopted the former course with respect to all sanctuaries and priesthoods.  Thenceforth the Roman community had its two guilds of Salii and two of Luperci, and as it had two forms of Mars, it had also two priests for that divinity—­the Palatine priest, who afterwards usually took the designation of priest of Mars, and the Colline, who was termed priest of Quirinus.  It is likely, although it can no longer be proved, that all the old Latin priesthoods of Rome—­the Augurs, Pontifices, Vestals, and Fetials—­originated in the same way from a combination of the priestly colleges of the Palatine and Quirinal communities.  In the division into local regions the town on the Quirinal hill was added as a fourth region to the three belonging to the Palatine city, viz. the Suburan, Palatine, and suburban (-Esquiliae-).  In the case of the original —­synoikismos—­ the annexed community was recognized after the union as at least a tribe (part) of the new burgess-body, and thus had in some sense a continued political existence; but this course was not followed in the case of the Hill-Romans or in any of the later processes of annexation.  After the union the Roman community continued to be divided as formerly into three tribes, each containing ten wardships (-curiae-); and the Hill-Romans—­whether they were or were not previously distributed into tribes of their own—­must have been inserted into the existing tribes and wardships.  This insertion was probably so arranged that, while each tribe and wardship received its assigned proportion of the new burgesses, the new burgesses in these divisions were not amalgamated completely with the old; the tribes henceforth presented two ranks:  the Tities, Ramnes, and Luceres being respectively subdivided into first and second (-priores-, -posteriores-).  With this division was connected in all probability that arrangement of the organic institutions of the community in pairs, which meets us everywhere.  The three pairs of Sacred Virgins are expressly described as representatives of the three tribes with their first and second ranks; and it may be conjectured that the pair of Lares worshipped in each street had a similar origin.  This arrangement is especially apparent in the army:  after the union each half-tribe of the tripartite community furnished a hundred horsemen, and the Roman burgess cavalry was thus raised to six “hundreds,” and the number of its captains probably from three to six.  There is no tradition of any corresponding increase to the infantry; but to this origin we may refer the subsequent custom of calling out the legions regularly two by two, and this doubling of the levy probably led to the rule