KULES OP CROSSING RECAPITULATED. 137 



any other breed to improve the Merino in any of the charac- 

 teristics now sought in that breed. 



II. That while an infusion of Merino blood is highly 

 beneficial to unimproved coarse families, to increase the 

 fineness and quality of their wool, it injures the improved 

 mutton races more in size, early maturity, propensity to 

 fatten and prolificacy in breeding than it benefits them in 

 respect to the fleece, or otherwise. 



III. That no valuable intermediate family of permanent 

 hereditary character has yet been formed, or is likely to be 

 formed, by crossing between Merinos and coarse sheep ; and 

 that the only successful continuous cross between them is 

 when the object is to merge a coarse-wooled family wholly 

 in the Merino, and when the breeding is steadily continued 

 toward the Merino (i. e., when no ram is ever used but the 

 full-blood Merino.) 



IV. That an infusion of the blood of one coarse-wooled 

 breed has been supposed, in a very few instances, to benefit 

 another coarse-wooled breed, but that as a general thing it is 

 much safer to avoid all crossing between distinct breeds. 



V. That crossing between different families of the same 

 breed, for the purpose of obtaining permanent sub-families, 

 has, both among the Merinos and English sheep, resulted 

 highly favorably in many instances ; but that, nevertheless, 

 the instances of failure have been much more numerous ; that 

 it is not expedient to cross even different families of the same 

 breed for this object, except in pursuance of a well-digested 

 and definite plan, founded on some experimental knowledge 

 of the subject ; and finally, that siich crosses (like all others) 

 should only be made when the necessary materials for the 

 desired improvement cannot be found within one of the 

 families (in other cases breeds) which it is proposed to cross 

 together. 



VI. That crossing between different families of the same 

 breed for the purpose of merging one family in another is 

 still more likely to prove successful : but that, in attaining 

 either this or the preceding object, it is desirable to unite 

 families presenting the fewest differences, and to limit the 

 cross to as few families as the circumstances admit of. 



VII. That for the purposes of mutton production it is 

 highly expedient to breed rams of the best mutton families 

 with ewes of hardier and more easily kept local families 

 but that, in such cases, it is almost uniformly advisable to 

 stop with the first cross. That such a system to produce 



