AGE OF 
and the central pair have very visibly shrunk, so 
as to leave intermediate spaces ; at fifteen months, 
the third pair are diminished, and no two teeth 
are'in mutual contact; and at eighteen months, 
all the incisors are so dwarfish and so far shrunk 
from another, that an inexperienced examinator 
wonders how the animal can contrive to eat a 
sufficient quantity of provender. 
During the whole of this process of absorption, 
not only the roots of the teeth as in man and the 
horse, but also the body and the crown, have been 
diminishing ; and, in its latter stage, or after the 
eighteenth month, it becomes slower in its pro- 
gress, operates upon the pairs of teeth in the 
order of their age, and so pertinaciously reduces 
them that each tooth is eventually no larger in 
the body than a crow-quill. During four or five 
months following the eighteenth, the central pair 
of incisors waste slowly away till they attain their 
minimum size. At the end of the second year, or 
a little before, the central pair of the permanent 
teeth push out the wasted remnants of their prede- 
cessors, and begin slowly to elevate their own body, 
large, spreading, and massive. At three years, the 
second pair of permanent incisorsare wellup. At 
four years, the third pair of permanent teeth are 
up; and the corresponding pair of milk teeth will 
_ sometimes be so huddled behind them, as to give 
| great annoyance to the animal, and to require to 
be extracted. At five years, the fourth or last 
pair of permanent incisors have appeared, but 
are small; and the central pair are beginning to 
be worn down in a flat or slightly inclined direc- 
tion at the edges. At six years, the last pair of 
incisors are full-sized, the flattening of the top 
extends over all the incisors, and the central pair 
_ begin to show a dark line in the middle, bounded 
by a line of indurated bone. At seven years, in 
ordinary circumstances, the dark line with bony 
_ boundary appears in all the teeth, and a second, 
_ broader, and more circular mark appears within 
it in the central pair; and at eight years, this 
second and more circular mark appears in all the 
incisors except the last pair; yet from six till nine 
years, the criteria are far from being exact, and 
will be modified, to the amount of several months, 
by the manner in which the animal is fed. At 
nine years, a process of absorption, similar to that 
which reduced the milk-teeth, but neither so 
rapid nor so powerful, has commenced, the cen- 
tral pair of teeth have become visibly smaller 
than their neighbours, and the two dark marks 
have been fused into one in all the teeth except the 
corner pair. At ten years, the second pair of in- 
cisors, as well as the first, are diminished in size; 
and the mark in all is smaller and fainter than 
before. At eleven years, the third pair are di- 
minished ; and all, except the corner pair, show a 
visible decrease in the mark. At twelve years, 
the corner pair are diminished; and the other 
three pairs have almost wholly lost the mark. In 
subsequent years, the teeth progressively dwindle 
and wear away; and after the fourteenth or the 
PLANTS. 
sixteenth year, they belong to an old and ex- 
hausted animal, and rarely serve to maintain her 
longer in full condition. 
or fair value to a dairyman after she is twelve 
years of age. The same criteria which show the 
successive ages of the cow, show those also of the 
bull and the ox. 
Age of Sheep.—The age of all horned sheep may, 
in a general view, be known from the rings of 
their horns ; yet not with much more certainty, 
nor with more protection from the tricks of 
knavery, than in the case of horned cattle. The 
horn of the sheep appears in the first year, and 
very often at birth ; and it grows a ring annually 
to the end of life-—The teeth, as in the case of 
black cattle, furnish better criteria than the 
horns. The sheep, in its second year, has two 
broad teeth; in its third year, four broad teeth ; 
in its fourth year, six broad teeth ; and in its fifth 
year, eight broad teeth. But after its fifth year, 
its age is known chiefly by the wearing of the 
teeth, and, in many or even most cases, cannot 
be accurately or even very proximately deter- 
mined. The lamb, at birth, has two milk teeth, 
and in the course of a few weeks, obtains all the 
other pairs. The sheep, about. the end of its first 
year, loses the central pair of the milk teeth; at 
eighteen months, loses the second pair of the milk 
teeth ; and at three years, displays only such teeth 
as are even and pretty white. The teeth of the 
full-mouthed animal—the sheep of five years of 
age—seldom continue long sound, but some be- 
come blunt, loose, black, and broken; and hence 
many sheep which have passed their prime— | 
especially such as have fed much on turnips— 
are, in technical phrase, broken-mouthed. ‘The 
criteria of the sheep’s age, while very indefinite 
after five years of age, are not even certain in the | 
earlier years, and must be understood as supply- 
ing only a general rule; for the permanent teeth 
appear in some cases much earlier, and in others 
considerably later, than the normal period.— | 
Magazine of Domestic Hconomy.— Buffon’s Natural 
Mistory.— Gibson on Horses — Youatt on the Horse. | 
—Culley on Live Stock.—Clater’s Catile Doctor.— 
Youatt on Cattle—Spooner on the Sheep.—Quar- 
terly Journal of Agricultwre—Loudons HEney. of 
Agriculture—Cuvier’s Animal Kingdom. 
AGE OF PLANTS. Either the average total | 
existence of any species of plants, or the parti- 
cular period of its existence at which any indi- 
vidual plant has arrived. The existence of a 
plant, in a general view, is commensurate with 
its performance of organic functions, and does 
not include the exertion of vital energy, either 
by reproduction or otherwise, after the plant is 
eradicated, cut down, or dismembered; and the 
existence of the short-lived kinds of plants ter- 
minates with the completion of a single fructifi- 
cation, while that of the long-lived kinds includes 
many fructifications, and extends beyond the last 
of them till exfoliation ceases, or the root is tornup 
or dissevered from the stem. Some of the minute 
A cow is seldom of full | 
| 
i 
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