WHAT MAT BE INHERITED 185 



those which are widely divergent; therefore, animals 

 of widely divergent form and color should not be bred 

 together. To secure strong inheritance in the off- 

 spring, the sire and dam should give visible evidence 

 that they have been produced by breeding along par- 

 allel lines. Two parallel streams of nearly the same 

 volume and rapidity of flow unite harmoniously; two 

 streams of unlike flow and volume, united at a sharp 

 angle, produce many counter currents and unexpected 

 results. 



What may be inherited? Nearly everything or any- 

 thing. It all depends on a multitude of conditions, and 

 it is impossible to know certainly, before the parents 

 are united, what defects of one or both of the parents 

 will be transmitted. Comparatively few blemishes, as 

 ring-bone, curb, spavin, and the like, are inherited; 

 but what is equally undesirable is too often transmitted 

 the lack of power of resistance. When the organs 

 which lack resisting power are put to severe tests, the 

 blemish which afflicted the parent, or something similar 

 to it, makes its appearance. Under favorable conditions 

 and absence of severe tests, especially when young, the 

 offspring, though from unsound parents, may, and often 

 does go through life unblemished. It is only in rare 

 cases that tuberculosis is inherited; but the lack of 

 power to resist the specific organism which produces 

 the disease may be inherited. All this leads to the 

 conclusion that pains should be taken to select such 

 strains of animals for breeding purposes as are known 

 to possess power to withstand, to a good degree, unusual 

 strain and adverse conditions. Individuals, and some- 



