AMONG SHEEP IN NEW SOUTH WALES. 
gat’d to that limited degree of crossing which is attainable in any 
establishment, by using the rams bred from one flock with the 
young ewes produced from another — a system judiciously and 
invariably practised by those who breed in-and-in upon principle. 
At all events, it seems justifiable, and at any rate safe, to 
assign as a main predisposing cause to this disease — “ constitu- 
tional deterioration from too close or injudicious breeding in-and- 
in where the nearest intercourse is permitted between sires and 
dams with their immediate offspring, and this for a lengthened 
period.” And perhaps, as allied to this cause, also from “ ex- 
cessive breeding,” where two crops of lambs are produced and 
reared in one year from the same ewe. 
In addition to these two causes, and sometimes combined with 
them, another source of diminished constitutional vigour, and 
lessened capability of resisting the disease, may arise from the 
effects of previous bad management in the treatment of cutaneous 
affections by mercurial remedies. 
It would not be correct to say, that the two last mentioned 
causes are applicable to many of the flocks which have suffered 
under the epidemic now prevalent ; but from what is known re- 
specting the general system of breeding followed in the colony 
by the most inexperienced stockholders, there are the strongest 
grounds for believing that the first named cause, degeneracy of 
constitution from injudicious breeding in-and-in, has been the 
chief predisposing cause in the majority, and that this first, com- 
bined with the last named two causes, have been the predisposing 
ones in many others. 
These views of the disease are strengthened by the facts, that 
not only the regularly crossed sheep, but all coarse-woolled sheep 
(which are seldom closely bred), are less subject to the disease 
than such as those just described ; or, if attacked, they suffer 
less, pr more readily surmount the effects of the disease. Sheep 
of all ages are liable to the epidemic, but more particularly the 
young ; and lambs when only eight days old, it has been recently 
noticed, are attacked and die. This mortality amongst lambs, it 
is material to observe, is prevailing unhappily to a great extent 
amongst the flocks on that establishment where the in-and-in 
system of breeding has been so closely pursued. 
The appearances after death are, generally, congestion in the 
vessels and coverings of the brain, and effusions of water into 
its cavities : inflammation of the mucous membranes of the nos- 
trils, frontal cavities, and fauces, sometimes also of the wind- 
pipe : in other instances, and when the disease has been of long 
continuance, ulceration of those parts may be met with. Con- 
gestion of the lungs will be found where the disease has taken a 
