For the purposes of scientific topography observation of the natural features and outlines is followed by exact investigation of the architectural structures or remnants, a process demanding high technical competence, acute judgment and practical experience, as well as wide and accurate scholarship. The building material and the manner of its employment furnish evidence no less important than the character of the masonry, the design and the modes of ornamentation.
He will therefore devote all his care to examine and distinguish these three means of knowledge; and seeing that truth and error can, properly speaking, be only in the intellect, and that the two other modes of knowledge are only occasions, he will carefully avoid whatever can lead him astray."
The modes of life and standards of comfort and morality in north Italy and in Calabria are widely different; the former being far in front of the latter.
The Udgatri's duties being mainly confined to the chanting of hymns made up of detached groups of verses of the Rigveda, as collected in the Samaveda-samhita, the more important Brahmanas of this sacerdotal class deal chiefly with the various modes of chanting, and the modifications which the verses have to undergo in their musical setting.
The only one of these possible modes of reproduction not known to occur in Hydromedusae is parthenogenesis.