The other characteristic marks of the domestic sheep—­the wool and the length of the tail—­vary greatly.  The heath sheep—­the little, contented, weather-hardened grazing sheep of the Lueneburg and other heaths—­belong to one of the oldest species, and their tails are as short and their horns as dark as those of the moufflon.  A cross between these two breeds is not distinguishable, even in the second generation, as has been shown by the interesting experiments in the Duesseldorf Zoological Garden.

[Illustration:  Heath sheep.]

The little, black and red-spotted Cameroons sheep, from the western coast of Africa, have not a trace of wool.  But why should they have?  The negroes need no clothing, and, consequently, they have not bred sheep with wool; and, besides, such an animal could not live in the tropics, even if the black man were a much better stock raiser and breeder than he is.  The mane on the neck, and breast of the Cameroons ram reminds one of the North American sheep; but it must be remembered that the mouflon and arkal rams have this ornament quite clearly, although not so strongly defined.

[Illustration:  Cameroons sheep.]

The large, short-bodied and long-legged sheep found in the interior of western and northern Africa are a complete contrast to the short-legged, long-bodied little Cameroons sheep.  There is a very valuable pair of the former in the Berlin Zoological Garden—­the Haussa sheep—­which are very regularly marked, the front parts of their bodies being red and the hind parts white.  They were brought from the neighborhood of Say, on the middle Niger, by the Togo Hinterland expedition.  The ram has beautiful horns, and the ewe is distinguished by two strange, tassel-like pendants of skin that hang from her neck.  This zoological garden also possesses a fine ram from the interior of Tunis, which is similar in shape to the Haussa ram, but has shorter horns and a heavier mane.  Its color is grayish black.

[Illustration:  Ram from Tunis.]

[Illustration:  Haussa ram.]

[Illustration:  Haussa ewe.]

Dr. Heck considers the long tail of the domestic sheep the chief impediment to the adoption of the theory of its descent from the short-tailed wild sheep.  And yet, in sheep, this member is of secondary importance, for it varies greatly in form.  The short-tailed heath sheep are just the opposite of the fat-tailed Persian sheep, which are represented in a fabulous account as being obliged to draw their broad tails, that weighed 40 pounds, behind them on wheels.  These are the sheep that supply the Astrakan and Persian lamb which is so much worn now.  The fur is caused to lie in peculiar waves or tight rings by sewing the newly born lamb in a tightly fitting covering which keeps the fur from being mussed.  In the Berlin Zoological Garden there is a very fine four-horned,