THE TEETH OF FOSSIL MAN 467 
shown In fig. 172, reaching its greatest manifestation in 
the gorilla and the least in man. We have reason to 
suppose that these various forms have all been evolved 
from a common type, and at the present time we have 
the strong hope that a better knowledge of the laws 
which regulate the growth and development of the body 
will reveal to us the exact manner in which these various 
degrees of caninism have been produced. In the stages 
shown in fig. 172 there is only one real break in the 
series — that between those represented by man and by 
the female chimpanzee. Does Eoanthropus serve to 
bridge that gap ? 
We have only the lower canine to help us in answering 
this question, and it forms only part of the canine shears. 
We have seen that the first lower premolar and the 
lateral incisor are also intrinsic parts of the canine 
mechanism. To give a complete answer we need not 
only the canine teeth but their neighbours on each side. 
The condition of the lower canine can only be explained 
by supposing that the canines had passed some little 
way from the anthropoid towards the human condition. 
We have seen that the crown of the Piltdown canine was 
worn in a peculiar manner, and that its dimensions were 
rather small when compared with those of anthropoid teeth. 
Occasionally we do find anthropoid dentitions in which the 
lower canines are worn in a manner not altogether unlike 
the wear seen in the Piltdown specimen. When such 
cases are examined it is found that the wear is due to the 
upper lateral incisor, and that the lower canines are less 
widely separated than is usual. 1 infer, therefore, that 
in Eoanthropus the lower canines had undergone an 
approximation, and that the partial twist which brought 
them more in line with the incisors than with the molar 
teeth had taken place. Their chief opponents were not 
the upper canines but the upper lateral incisors. In 
brief, there is an indication that the humanisation of the 
canines had begun in the Piltdown race. In the 
Heidelberg mandible, which Dr Smith Woodward 
supposes to have belonged to a form of mankind 
