There is reason to believe that sheep in their early domesticated condition
were "brown or dingy black;" but even in the time of David certain flocks were
spoken of as white as snow. During the classical period the sheep of Spain are
described by several ancient authors as being black, red, or tawny. (13/3.
'Youatt on Sheep' 1838 pages 17, 145.) At the present day, notwithstanding the
great care which is taken to prevent it, particoloured lambs and some entirely
black are occasionally, or even frequently, dropped by our most highly
improved and valued breeds, such as the Southdowns. Since the time of the
famous Bakewell, during the last century, the Leicester sheep have been bred
with the most scrupulous care; yet occasionally grey-faced, or black-spotted,
or wholly black lambs appear. (13/4. I have been informed of this fact through
the Rev. W.D. Fox on the excellent authority of Mr. Wilmot: see also remarks
on this subject in an article in the 'Quarterly Review' 1849 page 395.) This
occurs still more frequently with the less improved breeds, such as the
Norfolks. (13/5. Youatt pages 19, 234.) As bearing on this tendency in sheep
to revert to dark colours, I may state (though in doing so I trench on the
reversion of crossed breeds, and likewise on the subject of prepotency) that
the Rev. W.D. Fox was informed that seven white Southdown ewes were put to a
so-called Spanish ram, which had two small black spots on his sides, and they
produced thirteen lambs, all perfectly black. Mr. Fox believes that this ram
belonged to a breed which he has himself kept, and which is always spotted
with black and white; and he finds that Leicester sheep crossed by rams of
this breed always produce black lambs: he has gone on recrossing these crossed
sheep with pure white Leicesters during three successive generations, but
always with the same result. Mr. Fox was also told by the friend from whom the
spotted breed was procured, that he likewise had gone on for six or seven
generations crossing with white sheep, but still black lambs were invariably
produced.

Similar facts could be given with respect to tailless breeds of various