Thus much of the internal structure of the udder. Its external form requires attention, because it indicates different properties. Its form should be spheroidal, large, giving an idea of capaciousness; the bag should have a soft, fine skin, and the hind part upward toward the tail be loose and elastic. There should be fine, long hairs scattered plentifully over the surface, to keep it warm. The teats should not seem to be contracted, or funnel-shaped, at the inset with the bag. In the former state, teats are very apt to become corded, or spindled; and in the latter, too much milk will constantly be pressing on the lower tubes, or receptacle. They should drop naturally from the lower parts of the bag, being neither too short, small, or dumpy, or long, flabby, and thick, but, perhaps, about three inches in length, and so thick as just to fill the hand. They should hang as if all the quarters of the udder were equal in size, the front quarters projecting a little forward, and the hind ones a little more dependent. Each quarter should contain about equal quantities of milk; though, in the belief of some, the hind quarters contain rather the most. Largely developed milk-veins--as the subcutaneous veins along the under part of the abdomen are commonly called--are regarded as a source of milk. This is a popular error, for the milk-vein has no connection with the udder; yet, although the office of these is to convey the blood from the fore part of the chest and sides to the inguinal vein, yet a large milk-vein certainly indicates a strongly developed vascular system--one favorable to secretions generally, and to that of the milk among the rest.