OBSERVATIONS ON THE AGE OF THE OX. 
391 
both the use of teeth and dentition ought to be earlier in subjects 
weaned at so early an age and so soon fed with substantial food 
in abundance, since the quicker wear of the organs is a necessary 
consequence, hence their earlier replacement by teeth stronger and 
more resisting is a natural condition of such alimentation. 
Physiologically, again, we can understand that when, from what- 
ever cause, the entire orgasm assumes a more active development, 
the teeth, the same as other organs, ought, considered as parts of 
this orgasm, to participate in this general precocity, and conse- 
quently follow a more rapid course in their succession of evo- 
lution. 
Nevertheless, these opinions, which the data of science permit us 
to assume d priori , have their foundation demonstrated by observa- 
tion and practice. And such, 1 hope to prove to you, are the 
results of facts which I shall now bring forward by way of com- 
pleting my reply to the question you have done me the honour to 
address to me. 
Of all the known bovine race, the English Durham breed is, 
undeniably, the most remarkable for precocity of development. 
Its property of fattening quickly, and reaching full growth at an 
early age, constitute its character and recommendation. It is 
equally notorious, and cannot be denied, that this property, which 
has been conferred on the breed solely by good food and abund- 
ance of it, would speedily degenerate, and in the end become lost, 
if those destined to perpetuate it, or their offspring, were not them- 
selves maintained in the same condition by alimentation as that 
which produced it in the first instance. 
Now, such is precisely the case with the Durham oxen and 
those most resembling them, on which in dentition, and especially 
in the evolution of the permanent teeth, may be observed the pre- 
cocity which has given rise among the agriculturists of your part 
of the country, the incertitudes and doubts that you require to be 
cleared up. 
I could send you some observations I have made, relative to 
this subject, on oxen and cows of the Durham breed which I had 
occasion to visit at the dairy ( vacherie ) of Alfort ; but I prefer to 
communicate to you, as being more complete and therefore better 
calculated for your conviction, those made in the royal dairies 
of Pin and Poussery, by MM. the directors of those establish- 
ments, and which, from the manner in which they reached me, 
have all the value of official documents. I annex, literally copied, 
the questions I addressed to my very honourable colleagues, and 
the answers each of them kindly favoured me with. 
