There is a considerable difference in the qualities of muscular flesh, according to the size of the animal, and also according to its activity. The small mountain sheep, for example, which has to encounter fatigue to procure its food, has flesh of a different quality and flavour from the large and lazy creature, which feeds luxuriously and fattens rapidly, in the rich pastures of the plain country. The beef of the western islands also, is more esteemed, on account of the same circumstance, than that of the fat and brawny oxen which we see in the London market. It is for this reason, we have no doubt, that the flesh of the horse, the rhinocerus, and elephant, is not used as food except in cases when other food is not to be procured. In the circumstance of activity altering the qualities of flesh, we may be allowed to instance the superiority of venison to beef, in flavour and tenderness, and easiness of digestion. The age of animals is another circumstance which has great influence on the qualities of their flesh. The flesh of young animals is composed of less rigid fibres, and has fewer vessels which carry red blood running through it, and besides, it has less of the peculiar flavour of its particular species than the flesh of older animals. Gelatine is more abundant in the young, and fibrin in the old; hence the former is more bland and tender. Veal and lamb, for example, are more tender and gelatinous than beef or mutton; sucking pigs, chickens, and ducklings, are also much more delicate than the grown animals. The beef of an old cow, however well fed, is quite tough and unpalatable, while that of a very young heifer is much relished. Although, however, very young animals be so much more tender, yet they are insipid and flabby. In the case of pork, age is not required, as in other sorts of butcher meat, to mellow the fibre. It is an aliment containing much nourishment; but to some palates its flavour is disagreeable, though by most people it is relished. It was much used by the ancient athletæ, as half raw beef steaks are now by our men of the fancy. Sucking pigs are killed when three weeks old; and for pork, pigs are killed from six to twelve months old. It requires them to be older for making brawn. The flesh of young venison is not so good as when four years old or more; though that of the fawn is very tender and succulent. But even in the fœtal state, the flesh of animals, if recently taken from a healthy mother, may be used. In the London market the fœtus of the cow is regularly sold to the pastry-cooks for the purpose of making mock turtle soup, of which it often forms the principal portion.