The skull is mesocephalous, with an index of about 82; the forehead of good size, round and prominent; the face rather short, and often quadrilateral. The nose is somewhat broad, with rounded tip and nostrils, often short, and, when not straight, as is most common, is as frequently convex as concave. The eyes are large, horizontal, and placed widely apart, with black pupils and muddy yellow sclerotic; and the lips, which are well-formed and neither excessively prominent nor thick, are kept closed when at rest, and cover teeth strong though irregular and often stained from use of tobacco. The ears are of good shape, small, and lie close to the head. Their speech is rapid and vivacious. Each tribe possesses a distinct dialect, traceable, however, to the same source. "The Andamanese languages are one group, and have no affinities by which we might infer their connection with any other known group. They belong to the agglutinative stage of development, and are distinguished from other groups by the presence, in full development, of the principle of prefixed and affixed grammatical additions to the roots of words. Their form of speech is extremely intricate; for instance, the possessive pronouns have as many as sixteen possible variants according to the class of noun with which they are in agreement. There is also a distinct poetical dialect, and in their songs they subordinate to rhythm, not only the form of words, but even the grammatical construction of sentences."[101] They have words for the numerals "one" and "two" only, but can count to ten by tapping the nose with the finger-tips of both hands, uttering for each in turn the word _an-ká_ = "and this," until, when the last is reached, the expression _árdúru_ implies "all." In disposition they are childish, but bright and merry, though petulant, quick-tempered, and restless, and not capable of much perseverance. Great affection is lavished on children and the young; old or helpless are held in high consideration. Women are well treated, and not used as drudges or slaves, but are assisted by the men, who assume a fair share of the day's work. In the school that at one time existed at Port Blair for the Andamanese, it was found, that, as with all savages, the children, when educated were as proficient up to a certain age as the children of civilised peoples, but that point reached, they possessed no capacity for imbibing further knowledge. As the natives gain by education in intelligence and tractability, they become fat and indolent, while their morals undergo much deterioration through contact with the convicts. The clearance of the jungle has been prejudicial to their health, and excessive tobacco-smoking among both sexes, which has been unrestricted, has seriously undermined their already enfeebled constitutions.