we find the greatest variety not only in figure, height, and colour, but in every other quality. There are also other circumstances which contribute to this change. The life of the dog is short, his produce is frequent, and in pretty large numbers; he is perpetually beneath the eye of man, and whenever by an accident, which is very common in nature, there may have appeared an individual possessing singular characters, or apparent varieties, they have been perpetuated by uniting together those individuals, and not permitting them to intermix with any others; as is done in the present time, when we want to procure a new breed of dogs, or other animals. Besides, though all the species were equally ancient, yet the number of generations being necessarily the greatest in those whose lives are short, their varieties, changes, and even degenerations, must have become more sensible, since they must be further removed from their original stock than those whose lives are longer. Man is at present eight times nearer to Adam than is the dog to the first of his race, because man lives to fourscore years, and the dog to not more than ten. If, therefore, from any cause these two species equally degenerate, the alteration would be eight times more conspicuous in the dog than in man. Those whose lives are so short that they are succeeded every year by a new generation, are infinitely more subject to variations of every kind than those which have longer lives. It is the same with annual plants (some of which may be said to be artificial or factitious), when compared with other vegetables. Wheat, for example, has been so greatly changed by man that it is not at present to be any where found in a state of nature, it certainly has some resemblance to darnel, dog-grass, and several other herbs of the field, but we are ignorant to which its origin ought to be referred; and as it is renewed every year, and serves for the common food of man, so it has experienced more cultivation than any other plant, and consequently undergone a greater variety of changes. Man can, therefore, not only make every individual in the universe useful to his wants, but, with the aid of time, he can change, modify, and improve their species; and this is the greatest power he has over Nature. To have transformed a barren herb into wheat is a kind of creation, on which, however, he has no reason to pride himself, since it is only by the sweat of his brow, and reiterated culture, that he is enabled to obtain from the bosom of the earth this, often bitter, subsistence. Thus those species, as well among vegetables as animals, which have been the most cultivated by man, are those which have undergone the greatest changes; and as we are sometimes, as in the example of wheat, unable to know their primitive form, it is not impossible that among the numerous varieties of dogs which exist at present there may not be one like the first animal of