50 MOSTLY MAMMALS 
Commencing with the camel, it is probably known to 
most of my readers that there are two kinds of this animal— 
namely, the two-humped Bactrian camel (Camelus bactrianus) 
of Central Asia, and the one-humped Arabian camel (C. 
dromedarius), now common to Asia and North Africa. It 
has been affirmed that wild Bactrian camels occur in the 
deserts of Turkestan, but it is almost certain that some at 
least of these are descendants of a domestic race which 
escaped from captivity about two hundred and fifty years 
ago. Others may, however, be truly wild. The only clue 
to the original habitat of the genus is afforded by the 
remains of fossil camels in North-Eastern India, Eastern 
Europe, and Algeria ; and as the former occur in the older 
deposits, it seems probable that Central Asia is the cradle 
of the race. At what period the camel was first domesti- 
cated is lost in the mists of antiquity. From its absence 
in the Egyptian frescoes, it has been stated that this 
animal was unknown to the early inhabitants of the Delta 
of the Nile; but this is controverted by a papyrus of the 
fourteenth century B.c., in which reference is made to 
camels, 
Considering the very large number of existing wild 
species of the genus Ovzs, it is a very remarkable fact 
that we are unable to point to the ancestral stock of the 
sheep. As we know them in this country, domesticated 
sheep differ from their wild kindred by their woolly fleece, 
the wild species having hair more like that of a deer. But 
as some of the native domesticated sheep of Asia and 
Africa have a more or less hairy coat, the difficulty does 
not lie here. With the single exception of the arui, or 
Barbary sheep of Northern Africa, all wild sheep have 
short tails; whereas in the domesticated races this appen- 
dage, until docked, is very long. The reader may ask why 
