-3793- on varieties of domestic animals. 159 
ent individual might in time appear, perhaps with a 
more hairy fleece than the improved parent stock, 
it would of course be banifhed fromthe breed ; and 
when another individual, with still purer wool might 
be produced, this one being again selected to breed 
from, occasions an additional refinement. In this way 
it might happen that in course of time, by a con- 
tinued care, a fheep might at last be found, among 
the wool of which there were no hairs at all; and 
this also being selected would afford a breed with 
wool entirely free from hair, unlefs upon an acci- 
dental individual, which would of course be separa~ 
ted from the breeding stock whenever it appear. 
ed*, 
* A singular instance of the powerful tendency that animafs in a 
state of nature have to preserve the separate varieties distinct, o¢- 
curs in regard to the Shetland breed of theep, so justly celebrated for 
the unequalled softnefs of its pile, and brilliancy of its colour. In 
the Shetland isles, though the fheep are not entirely in a wild state, 
they are so nearly so, as scarcely to deserve the name of a domestic 
animal, and suffer no other effect from the care of the owner than 
those which tend to deteriorate the breed ; yet in spite of these efforts 
to debase it, continued for ages, there are still remains of that breed 
tolerably pure in that place. The measures that have been taken to 
debase it are as under: 
1. Foreign breeds, producing hard coarse wool, have been often in- 
troduced into these isles. But the nimble active native theep, fre. 
quenting in geneyal the more desolate wilds at the greatest distance 
from the dwellings of the natives, in some measure withdraw them- 
selves from the others, like the Tartar Nomades from the Rufsian peae 
sants, and thus get the breed only partially debased by accidental 
stragglers. 
2. Asthe natives scarcely look at their fheep save once a year, 
and do not fheer the wool, but gather it.szpon the heath as it falls 
from the animal ig handfuls, they have had no opportunity of remark- 
