of the Animals of the Farm. 
419 
Fig. 28. — Incisors of Heifer at one year and ten months. 
In the next illustration (Fig. 29, p. 420) the sixth molar is 
shown in the position described, and in the same figure the 
first and second permanent molars have taken the places of the 
temporary teeth ; this change, in my own experience, does not 
usually occur until the animal is a month or two over two 
years of age. 
From two years and three months to two years and six 
months the second pair of broad teeth, the middle permanent 
incisors, occupy the place of the corresponding temporary teeth 
in all the cultivated breeds. Instances of late dentition present 
themselves from time to time, in which the middle permanent 
incisors are not cut until the animal is approaching three years 
old. There is consequently a possible variation of six months 
in the time of the appearance of these teeth. 
In the illustration (Fig. 30, p. 420), the ordinary condition 
of the incisors at two years and six months is shown. 
2 E 2 
