Guenoris System of Selecting Cows hy the Escutcheon. 471 
come ; at the age of sixteen or eighteen the teeth have generally 
fallen out. At this period the age can be determined with more 
or less certainty by the horns. 
Until the end of the third year the horns are smooth ; from 
this period a ring elevation forms around them near the head, 
and a new ring forms after this period with every year. A 
smooth horn counts for two years ; one ring for three years ; 
and to every ring one additional year is reckoned. According 
to this calculation an animal with seven rings is nine years old. 
In the ox these rings are less distinct than in the cow. This 
may, perhaps, be partly owing to her gestating ; for, during the 
year that a cow is without calf, no ring forms on her horns, or, 
if a ring forms, it is scarcely perceptible. In such a case the 
interval between the two rings is twice as large as usual, and 
counts for two years. If the rings should not be very distinct, 
we may judge of the age of the animals by the condition of the 
horns themselves, which become thinner towards their roots in 
proportion as the animals approach their full growth. Horned 
cattle may attain to the age of twenty years without, however, 
remaining equally useful. 
5. The Period of Gestation. — Nine months is the general 
period for this process of nature, though it is usually exceeded 
by one or two weeks, two hundred and eighty days being the 
ascertained average. The cow in her wild or natural state would 
most probably conceive again three weeks after dropping her 
calf; and as nature demands that all the resources of the cow's 
being shall be devoted to developing the new foetus, and the 
milk undergoes a slight change for that purpose, she would 
nourish her calf for about eight weeks, and partially for two 
months longer, and the milk would soon thereafter dry up, in 
order that she should not be carrying on two processes at once. 
But civilization has effected great changes in her nature, and 
we force her to develop both operations at one time, viz., her 
milking and breeding duties. To do this we are obliged to be 
regular in the milking and feeding, and feeding heavier and 
more constantly than she would be able to do in an untamed 
state. This stimulation perverts her nature and develops the 
lacteal glands and the udder to hold the increased quantity of 
milk to an enormous extent. Therefore we find many cows, 
and all, more or less, very much more developed than they 
would be in a state of nature. 
Now, this process of cessation of milk in order to develop 
the new foetus is certain and continuous, and the milk diminishes 
more or less from the impregnation. With some the lacteal 
glands have become so developed that the animal never entirely 
ceases to give milk between one calf and another. However 
