Chap. III. CAUSES OF VAKIATION. 103 



great autliority, namely, Loi'd Somerville, remarks, " the 

 wool of our Merino sheep after shear-time is hard and coarse 

 to such a degree as to render it almost impossible to suppose 

 that the same animal could bear wool so opposite in quality, 

 compared to that which has been clipped from it : as the 

 cold weather advances, the fleeces recover their soft quality.'' 

 As in sheep of all breeds the fleece naturally consists of 

 longer and coarser hair covering shorter and softer wool, the 

 change which it often undergoes in hot climates is probably 

 merely a case of unequal development ; for even with those 

 sheep which like goats are covered with hair, a small quantity 

 of underlying wool may always be found. ^^ In the wild 

 mountain-sheep (^Ovis montana) of North America there is an 

 analogous annual change of coat ; " the wool begins to drop 

 out in early spring, leaving in its place a coat of hair resem- 

 bling that of the elk, a change of pelage quite different in 

 character from the ordinary thickening of the coat or hair, 

 common to all furred animals in winter, — for instance, in the 

 horse, the cow, &c., which shed their winter coat in the 

 spring." ^* 



A slight difference in climate or pasture sometimes slightly 

 affects the fleece, as has been observed even in different districts 

 in England, and is well shown by the great softness of the 

 wool brought from Southern Australia. But it should be 

 observed, as Youatt repeatedly insists, that the tendency to 

 change may generally be counteracted by careful selection. 

 M. Lasterye, after discussing this subject, sums up as 

 follows : " The preservation of the Merino race in its utmost 

 purity at the Cape of Good Hope, in the marshes of Holland, 

 and under the rigorous climate of Sweden, furnishes an ad- 

 ditional support of this my unalterable principle, that fine- 

 woolled sheep may be kept wherever industrious men and 

 intelligent breeders exist," 



That methodical selection has eff"ected great changes in 



" Youatt on Sheep, p. 69, where tion counteracting any tendency to 



Lord Somerville is quoted. See p. 117, change, see pp. 70, 117, 120, 168. 



on the presence of wool under the ** Audubon and Bachman, ' The 



hair. With respect to the fleeces of Quadrupeds of North America,' 1S46, 



Australian sheep, p. 185. On selec- vol. v. p. 365. 



