458 THE ANTIQUITY OF MAN 
and rises 14 mm. above the neck — the constriction sur- 
rounded by the gum. In female anthropoids, the canines 
being much smaller than in the males, the crowns 
rise from 16 to 20 mm. above the neck. In modern 
human races the canine crowns are never shaped as in 
the Piltdown specimen, and rarely rise more than 12 
or 13 mm. above the level of the neck. The greatest 
diameter of the crown — from the outer or labial margin 
to the inner or lingual — is somewhat less than Dr Smith 
Woodward had postulated (i4'5 mm.). It measures just 
under 1 1 mm., a dimension never reached in the canines 
of modern man ; in them the greatest diameter rarely 
exceeds 9 mm. In Neanderthal man this measurement is 
frequently exceeded (fig. 169), but in shape the Neander- 
thal canines are merely swollen forms of the modern 
type. The root of the Piltdown tooth is anthropoid in 
shape and dimensions. The exact length of the root is 
doubtful, the tip being broken away, but it was probably 
not less than 20 mm. in extent. In female anthropoids 
the roots are about 25 mm. long ; in modern human 
races they seldom exceed 18 mm. 
The original features of the crown or chewing surface 
cannot be discerned now. It is deeply hollowed by wear. 
On the excavated area can be seen a black circle marking 
the site of the exposed pulp cavity. Although the 
original characters of the crown have been rubbed away 
by use, we cannot doubt they were those seen on the 
unworn crowns of the canine teeth of apes and men (see 
fig. 169). On the lingual aspect of the chimpanzee's 
canine (fig. 169) a ridge is seen to descend from the tip 
to the heel of the crown, the heel being raised. The 
ridge lies between two functional surfaces. The anterior 
surface plies against the upper lateral incisor, and may 
therefore be named the " incisor " area. The hinder 
surface is opposed to the inner or lingual surface of the 
corresponding upper canine tooth ; the two surfaces 
represent the opposite blades of the canine shears. In 
the canine of the human infant (fig. 169) the same two 
surfaces are seen — incisor and canine. They are also 
