120 AMERICAN HUSBANDRY. 



breeding is to employ animals of both sexes imitmg 

 the highest qualities of the improved race ; but there 

 are always difficulties attending the conservation of 

 such a race, and, without the greatest care, a dete- 

 rioration from this elevated point will soon be visible. 



The cause and reason for this tendency to deteri- 

 oration must be sought in the impure blood which 

 necessaril}' exists in everj- deviation from an origi- 

 nal stock. Notwithstanding the value of the cross — 

 although it may approach the pure race to within 

 the minutest shade — still it carries in its blood, de- 

 rived from its mother, an indestructible germe of de- 

 basement ; always ready to develop itself by Uttle 

 and little, under the operation of local influences i 

 always modifying the general economy and consti- 

 tution of the animal, until, at length, by alteration of 

 form, and changes in the quahtieyand disposition of 

 the animal, it is evident that the tj"pe of the male 

 parent is effaced, and a reproduction of that of the 

 mother, with all its characteristics of inferiority, is 

 complete. 



It is clear, therefore, that though, by extraordina- 

 ry care and attention, an improved breed of animals 

 may be kept at any degree of excellence by select- 

 ing the best animals of the race to propag<^te from, 

 the breeder acts wisely, who occasionally regener- 

 ates his improved stock by crossing it with pure- 

 blood from the original race, without any ignoble 

 mixture or impure stain. The observance of this 

 rule appears to have constituted the secret of the 

 Rev. Henrj' Barry's unequalled success in breeding 

 improved Short Horns ; and a recurrence to it will, 

 we think, be found necessary by ever\- one who is 

 engaged in rearing the best animals of any breed. 



If a half-breed bull is put to a cow of" the same 

 grade, the character of the progeny would, accord- 

 ing to the mathematical calculations we have made, 



, , 050-f-050 102 , . . 



appear to be i = — = 0.50; that is, the 



