Vallum

Vallum is a term applied either to the whole or a portion of the fortifications of a Roman camp. The vallum usually comprised an earthen or turf rampart (Agger) with a wooden palisade on top, with a deep outer ditch (fossa). The name is derived from vallus (a stake), and properly means the palisade which ran along the outer edge of the top of the agger, but is usually used to refer to the whole fortification.

Characteristics

The stake-like valli (χάρακες) of which the vallum palisade was composed are described by Polybius (xviii.18.1, Excerpt. Antiq. xvii.14) and Livy (Liv. xxiii.5), who make a comparison between the vallum of the Greeks and that of the Romans, very much to the advantage of the latter. Both used for valli young trees or arms of larger trees, with the side branches on them; but the valli of the Greeks were much larger and had more branches than those of the Romans, which had either two or three, or at the most four branches, and these generally on the same side. The Greeks placed their valli in the agger at considerable intervals, the spaces between them being filled up by the branches; the Romans fixed theirs close together, and made the branches interlace, and sharpened their points carefully. Hence the Greek vallus could easily be taken hold of by its large branches and pulled from its place, and when it was removed a large opening was left in the vallum. The Roman vallus, on the contrary, presented no convenient handle, required very great force to pull it down, and even if removed left a very small opening. The Greek valli were cut on the spot; the Romans prepared theirs beforehand.(Polyb. l.c.; Virg. Georg. iii.346, 347; Cic. Tusc. ii.16). They were made of any strong wood, but oak was preferred.

Lingual papilla

Lingual papillae (singular papilla) are the small, nipple or hair–like structures on the upper surface of the tongue that give the tongue its characteristic rough texture.

There are four types of lingual papillae on the human tongue: circumvallate papillae (vallate papillae), fungiform papillae, filiform papillae and foliate papillae. All except the filiform papillae are associated with taste buds.

Structure

In living subjects, lingual papillae are more readily seen when the tongue is dry. There are four types of papillae present on the tongue:

Filiform papillae

Filiform papillae are the most numerous of the lingual papillae. Unlike the other kinds of papillae, filiform papillae do not contain taste buds. They cover most of the front two thirds of the tongue's surface.

They appear as very small, conical or cylindrical surface projections, and are arranged in rows which lie parallel to the sulcus terminalis. At the tip of the tongue, these rows become more transverse.

Histologically, they are made up of irregular connective tissue cores with a keratin–containing epithelium which has fine secondary processes. Heavy keratinization of filiform papillae, occurring for instance in cats, gives the tongue a roughness that is characteristic of these animals.

Vallum (disambiguation)

A vallum is the whole or a portion of the fortifications of a Roman camp.

Vallum may also refer to:

See also