to the use for which they are kept? How many ever sit down to calculate the difference in money value between an animal which barely pays for keeping, or perhaps not that, and one which pays a profit?

Let us reckon a little. Suppose a man wishes to buy a cow. Two are offered him, both four years old, and which might probably be serviceable for ten years to come. With the same food and attendance the first will yield for ten months in the year, an average of five quarts per day,—and the other for the same term will yield seven quarts and of equal quality. What is the comparative value of each? The difference in yield is six hundred quarts per annum. For the purpose of this calculation we will suppose it worth three cents per quart—amounting to eighteen dollars. Is not the second cow, while she holds out to give it, as good as the first, and three hundred dollars at interest besides? If the first just pays for her food and attendance, the second, yielding two-fifths more, pays forty per cent. profit annually; and yet how many farmers having two such cows for sale would make more than ten, or twenty, or at most, thirty dollars difference in the price? The profit from one is eighteen dollars a year—in ten years one hundred and eighty dollars, besides the annual accumulations of interest—the profit of the other is—nothing. If the seller has need to keep one, would he not be wiser to give away the first, than to part with the second for a hundred dollars?

Suppose again, that an acre of grass or a ton of hay costs five dollars, and that for its consumption by a given set of animals, the farmer gets a return of five dollars worth of labor, or meat, or wool, or milk. He is selling his crop at cost, and makes no profit. Suppose by employing other animals, better horses, better cows, oxen and sheep, he can get ten dollars per ton in returns. How much are the latter worth more than the former? Have they not doubled the value of the crops, and increased the profit of farming from nothing to a hundred per cent? Except that the manure is not doubled, and the animals would some day need to be replaced, could he not as well afford to give the price of his farm for one set as to accept the other as a gift?

Among many, who are in fact ignorant of what goes to constitute merit in a breeding animal, there is an inclination to treat as imaginary and unreal the higher values placed upon well-bred animals over those of mixed origin, unless they are larger and handsomer in proportion to the price demanded. The sums paid for qualities which are not at once apparent to the eye are stigmatized as fancy prices. It is not denied that fancy prices are sometimes, perhaps often paid, for there are probably few who are not willing occasionally to pay dearly for what merely pleases them, aside from any other merit commensurate to the price.

But, on the other hand, it is fully as true that great intrinsic value for breeding purposes may exist in an animal and yet make very little show. Such an one may not even look so well to a casual observer, as a grade, or cross-bred animal, which although valuable as an individual, is not, for breeding purposes, worth a tenth part as much.

Let us suppose two farmers to need a bull; they go to seek and two are offered, both two years old, of similar color, form and general appearance. One is offered for twenty dollars—for the other a hundred is demanded. Satisfactory evidence is offered that the latter is no better than any or all of its ancestors for many generations back on both sides, or than its kindred—that it is of a pure and distinct breed, that it possesses certain well known hereditary qualities, that it is suited for a definite purpose, it may be a Short-horn, noted for large size and early maturity, it may be a Devon, of fine color and symmetry, active and hardy, it may be an Ayrshire, noted for dairy qualities, or of some other definite breed, whose uses, excellencies and deficiencies are all well known.

The other is of no breed whatever, perhaps it is called a grade or a cross. The man who bred it had rather confused ideas, so far as he had any, about breeding, and thought to combine all sorts of good qualities in one animal, and so he worked in a little grade Durham, or Hereford to get size, and a little Ayrshire for milk, and a little Devon for color, and so on, using perhaps dams sired by a bull in the neighborhood which had also got some "Whitten"[1] or "Peter Waldo" calves, (though none of these showed it,) at any rate he wanted some of the "native" element in his stock, because it was tough, and some folks thought natives were the best after all. Among its ancestors and kindred were some good and some not good, some large and some small, some well favored and fat, some ill favored and lean, some profitable and some profitless. The animal now offered is a great deal better than the average of them. It looks for aught they can see, about as well as the one for which five times his price is asked. Perhaps he served forty cows last year and brought his owner as many quarters, while the other only served five and brought an income of but five dollars. The question arises, which is the better bargain? After pondering the matter, one buys the low-priced and the other the high-priced one, both being well satisfied in their own minds.

What did results show? The low-priced one served that season perhaps a hundred cows; more than ought to have done so, came a second time;—having been overtasked as a yearling, he lacked somewhat of vigor. The calves came of all sorts, some good, some poor, a few like the sire, more like the dams—all mongrels and showing mongrel origin more than he did. There seemed in many of them a tendency to combine the defects of the grades from which he sprung rather than their good points. In some, the quietness of the Short-horn degenerated into stupidity, and in others the activity of the Devon into nervous viciousness. Take them together they perhaps paid for rearing, or nearly so. After using him another year, he was killed, having been used long enough.

The other, we will say, served that same season a reasonable number, perhaps four to six in a week, or one every day, not more. Few came a second time and those for no fault of his. The calves bear a striking resemblance to the sire. Some from the better cows look even better in some points, than himself and few much worse. There is a remarkable uniformity among them; as they grow up they thrive better than those by the low priced one. They prove better adapted to the use intended. On the whole they are quite satisfactory and each pays annually in its growth, labor or milk a profit over the cost of food and attendance of five or ten dollars or more. If worked enough to furnish the exercise needful to insure vigorous health, he may be as serviceable and as manageable at eight or ten years old, as at two; meantime he has got, perhaps, five hundred calves, which in due time become worth ten or twenty dollars each more than those from the other. Which now seems the wiser purchase? Was the higher estimate placed on the well bred animal based upon fancy or upon intrinsic value?

The conviction that a better knowledge of the principles of breeding would render our system of agriculture more profitable, and the hope of contributing somewhat to this end, have induced the attempt to set forth some of the physiological principles involved in the reproduction of domestic animals, or in other words, the laws which govern hereditary