We frequently find worms in the livers of animals; a description of those found in sheep and oxen is contained in the Journal des Savans of 1668, and in the German Ephimerides. It was thought that these worms were peculiar to animals who chew the cud, but M. Dauberton discovered some in the liver of an ass, and it is probable they might be found in those of many other animals. It has also been said that butterflies are sometimes found in the livers of sheep; and in confirmation of this M. Rouillé favoured me with a letter of M. Gachet de Beaufort, containing the following observations: "It has long been remarked, that our Alpine wedders frequently lose their flesh on a sudden; that their eyes turn white and gummy, that their blood becomes serous, having scarcely any red globules, their tongues parched, and their noses stuffed with a yellow purulent mucus. It is true this does not affect the appetite of the animal, but makes him extremely weak and terminates in his death. From repeated dissections it has been discovered, that animals so affected have always butterflies in their livers, which butterflies are white, and furnished with wings; their heads are nearly oval, hairy, and about the size of those of the silk-worm fly. Above seventy which I squeezed out of the two holes convinced me of the truth of this fact." From this description of M. Beaufort I cannot admit myself as positively convinced of their being butterflies, because they have so near a resemblance to the common worms found in the livers of sheep, which are flat, broad, and of so singular a figure, as to appear at first rather leaves than worms.
It is customary for sheep to be shorn every year; and in warm countries where they apprehend no danger from leaving the animal quite bare, they do not shear the wool, but tear it off, and those frequently find a sufficiency to have two crops in a year. In France, and in colder climates, the fleece is shorn only once a year, and then a part of the wool is permitted to remain by way of preserving the animal from the intemperance of the weather. This operation is performed in the month of May, after the sheep have been well washed to render the wool as clean as possible. The month of April is too cold, and if delayed to July, there would not be sufficient time for the wool to grow to preserve them from the cold of the following winter. The wool of the wedder is generally better, and in greater abundance than that of the ewe or ram; that on the neck and top of the back, is much superior to that on the thighs, belly, tail, &c. and that taken from the bodies of the dead, or diseased animals, is by much the worst. White wool is preferable to grey, brown, or black, because in dying it will take any colour, and that which is smooth and sleek is better than the curled; it is even said, that sheep whose wool is curled are not so good as the others. Folding sheep is of great advantage to the land, and when it is wished to improve any by this means, the ground must be inclosed, and the flock shut in every night during the summer; the dung, urine, and heat of the animals, will soon enrich the most exhausted, cold, and infertile grounds. An hundred sheep in one summer will fertilize eight acres of land for six years.