ALTERATIONS INDUCKD B^ CKOSSINQ. 



27 



of our small northern varieties, are famed for the very 

 opposite characteristics. 



According to the opinion on the continent, any 

 race of ewes, however coarse and long in the fleece, 

 will, on the fourth cross of the merino ram, give 

 progeny with short wool equal to the Spanish. The 

 truth of this proposition is however doubted, in a 

 communication to the Board of Agriculture, by Dr 

 Parry of Bath ; but it is certain, he adds, that one 

 cross more will in most cases effect the desired purpose. 

 " If we suppose," he says, " the result of the admixture 

 of the blood of the merino ram to be always in an 

 exact arithmetical proportion, and state the native 

 blood in the ewe as 64, then the first cross would give 

 f^ of the merino, the second ^|, the third ||, the 

 fourth 15, the fifth ||, and so on. In other words, 

 the first cross would leave 32 parts in 64, or half of the 

 English quality ; the second 16 parts, or one-fourth ; 

 he third 8 parts, or one-eighth ; the fourth four parts, 

 or one-sixteenth ; the fifth 2 parts or one-thirty-second ; 

 the sixth 1 i)art, or one-sixty-fourth ; and so on. Now, 

 if the filament of the Wiltshire, or any other coarse 

 wool, be in diameter double that of the Ryeland, it is 

 obvious that, accojding to the above statement, it 

 would require exactly one cross more to bring the 

 hybrid wool of the former to the same fineness as that 

 of the latter. This, I believe, very exactly corresponds 

 with the fact. The difference between one-eighth and 

 one-sixteenth is very considerable, and must certainly 

 be easily perceived, both by a good microscope, and 

 in the cloth which is manufactured from such wool. 

 In the latter method, it certainly has been perceived j 



