as indicative of the Age of the Animal. 
331 
3, 3. They arc smaller in size even when fully developed than the 
second pair, but laro^er, as will be seen by-and-by, than the fourth 
or corner pcrnianent teeth. Besides there being six " broad teeth" 
in tlie mouth .at three years, those first put up will now begin to 
show slight wear. Their enamel edge will be cut through, ex- 
posing the dentine and forming thereby a slight hollow imme- 
diately behind the reflection of enamel which covers the front 
surface of the tooth. The colour of this hollow contrasts with 
that of the enamel, being of a darker shade. Its depth and size 
mark the amount of wear. The two temporary teeth which are 
still standing are often so reduced in size, from absorption and 
attrition, as to be overlooked when the mouth is hurriedly ex- 
amined. 
From this date we pass to three years and a quarter, when, in 
animals of early maturity, the fourth pair of incisors will occupy 
the places of the temporary, and will tlius complete the dentition 
of the ox. These teeth, as we might expect, will offer most 
variations as to the time of their cutting. By far the larger 
number of oxen will not put them up till after three years and a 
quarter, and I have repeatedly examined animals whose ages 
ranged from three and three quarters to four years and found 
these teeth in the act of cutting. On the other hand, I have 
occasionally seen them in Short-horn bulls, fairly through the 
gum at three years and a month. These things should guide the 
opinion of an examiner. If an animal is certified to be three 
years old, or wanting that time by a week or two, and all the 
incisors are permanent ones, it most certainly is a proper case 
for investigation, so few are the exceptions of these teeth being 
cut before three years and a quarter. Fig. 33 gives an illustra- 
tion of a " full mouth " at three years and a quarter ; so called 
because the teeth are all permanent. 
In cases of early dentition the judgment will often be assisted 
by the examiner noting the amount of the overlapping of the in- 
cisors, wliich is best seen on their upper surface. Thus the 
outer edges of the middle teeth are partially covered by the inner 
edges of the second, the second by the third, and the third by the 
fourth or corner incisors. This overlapping of the edges of these 
teeth arises from their broad and flat crowns being at their height 
of development when they penetrate the gums, and from the rapi- 
dity with which one pair has succeeded another, while the jaw 
has not yet fully adapted itself to their larger size. These things 
are nicely shown in the illustration of the mouth of the three 
years and a quarter old ox. 
In judging of age, the fulness also, and redness of the gums 
combined with the extent of protrusion of the incisors last cut is 
to be considered. In about two months from the appearance of 
