134 EGBERT BENNETT BEAN 



and those of Magitot-Broca are about the same as for the 

 Ann Arbor American boys. The Americans and the French 

 appear to be more precocious than the Germans. The Enghsh 

 are precocious in the eruption of the lateral premolars, and back- 

 ward in the eruption of the lateral incisors, but otherwise they 

 conform fairly well in the eruption of the teeth to the Germans. 



It is generally recognized that girls are more precocious than 

 boys in the eruption of the teeth, and that the lower teeth erupt 

 earlier than the upper, except the premolars, but Livy found 

 among 4,000 children of the workers of Bolton, England, that 

 the upper canines invariably precede the lower in the girls, whereas 

 the lower canines invariably precede the upper in the boys. The 

 upper canines erupt a year later than the lower among the Ger- 

 man, American and Filipino girls that I examined, and less than a 

 year later among the boys of the three groups. 



Spokes (48) found among British children that the eruption 

 of the canines occurs between the time of eruption of the median 

 and lateral premolars, which is a verification of what I found 

 among the German and American children of Ann Arbor, but 

 among the Filipinos the canines erupt before the premolars. 1 

 found that the lower canines erupt between the time of eruption 

 of the upper and lower median premolars, and the upper canines 

 erupt between the time of eruption of the upper and lower lat- 

 eral premolars. This may explain the contention of Owen (51) of 

 England on the one side, who contends that the canines erupt 

 before the premolars (canines, 7 to 9 years, premolars, 8 to 10 

 years), and Welcker, Sommering (51), Hyrtl (51), Henle (54), and 

 Blumenbach (51) on the other, who contend that the median 

 premolars erupt before the canines. It may be, however, that 

 the canines erupt earlier among the British than among the Ger- 

 mans, just as the canines erupt earlier among the Filipinos than 

 among the children of Ann Arbor, or at least this may be true for 

 some parts of the British Empire. Livy did not find it so for the 

 children of the laboring classes of Bolton, England. 



The work of Cherot is of value because it is of recent date, and 

 because he procured data from 20 to 30 children of each sex at 

 each age. The time of the beginning of eruption and of the 



