THE CROSSING, &C, OP PIGS. 291 



"Chiefly in consequence of so much crossing" (p. 

 101, Vol. i, Animals and Plants, &c), "some well 

 known breeds have undergone rapid changes; thus, 

 according to Nathusius, the Berkshire breed of 1780, 

 is quite different from that of 1 8 10; and, since this 

 latter period, at least two distinct forms have borne the 

 same name." 



