I/iJiuence of Climate, Sec, on Sheep. 
101 
climate, or tlicy must be rendered more hardy, in other words, 
less perfect in the special features which now recommend them 
to public favour. 
Mountain sheep, of all breeds, are remarkable for possessing 
great constitutional strength, whereby they can withstand 
severities of climate that would be fatal to more delicate animals. 
In speaking, however, of constitutional strength and delicacy of 
health, a clear understanding of what is meant by these terms is 
desirable, since without such understanding we are liable to 
overlook the simple truths they express. These distinctions 
spring from the action of a beneficent law of nature, whereby 
animals become naturalised to certain districts — that is, within 
certain limits they undergo such a variation of bodily form and 
character as qualify them to withstand the peculiarities of any 
special soil and climate. If too great and too sudden a transi- 
tion be attempted the animal perishes at the outset, but other- 
wise it becomes year by year and generation after generation 
more and more completely adapted to its home with its attendant 
circumstances. 
The variations in constitution, which under these circumstances 
arise, may be thus characterised : — 
A constitution is strong when the functions of the animal 
system can be discharged in a healthy manner under trying varia- 
tions of food and climate. 
A constitution is sound when the animal grows and thrives 
under the variations commonly found in a state of nature. 
A constitution becomes delicate when, through the intervention 
of man, and by a diminution of exposure, certain tendencies are 
fostered at the sacrifice of vital energies, so that the animal 
becomes specially subject to disease, and particularly so if re- 
stored to its orig-inal state of nature. The sireng-th of constitu- 
tion, for which our mountain sheep are remarkable, may therefore 
be traced to the fact that by natural laws they have, under trying 
circumstances, attained a healthy development of body which 
has not been interfered with by the refinements of ordinary 
agricultural practice. 
■ Mountain sheep are also remarkable for being qood breeders, 
and having a good supplg of milk. Circumstances which promote 
health of body are at the same time equally favourable to the 
exercise of the reproductive powers ; consequently animals noted 
for constitutional strength are also remarkable for being good 
breeders. There is also an intimate connexion between the 
reproductive organs and the mammary glands by which the milk 
is secreted. If the former act in a healthy and vigorous manner, so 
also do the latter, provided that a sufficient and proper supply of 
food be given. The three qualifications — constitutional strength, 
