1906.] BREEDING ANIMALS ON THE FARM. 163 



are so regular and uniform, that the man who diligently ap- 

 plies them will, with unfailing certainty, so improve the aver- 

 age of the animals in his stud, herd or flock, that they will be 

 brought to a higher level. 



The known laws that govern breeding are three in number. 

 They are known respectively as the law that like produces like, 

 the law of variation and the law of atavism. The first and 

 second of these laws are apparently antagonistic. The third, 

 like a pendulum in operation, swings between the two. 



The law that like produces like, means that the progeny 

 shall be like the parents, not an exact facsimile, for two parents 

 are never found exactly alike, but in all essential features there 

 will be a close resemblance. This resemblance will, with more 

 or less of uniformity, extend to the physical form, to function, 

 to habit, to disposition, and indeed to every feature of the or- 

 ganization. This law is the great Magna Charta of the breeder. 

 The results from the operation of this law are by no means 

 uniform. They will be nearly so, however, in proportion as the 

 parents have been purely bred, in proportion as they have been 

 bred in line without having reached the danger point of weak- 

 ened stamina, and in proportion as the parents are strong and 

 vigorous. 



The law of variation, or the law that like does not always 

 produce like, is apparently antagonistic to the law of likeness. 

 It means that the progeny shall not always be like the parents. 

 Though apparently antagonistic to the first law, it may be sim- 

 ply a part of the same, the differences being the result of modi- 

 fying factors in transmission as yet not well understood, and 

 until understood, beyond the control of man. In breeding 

 pure blood animals, these differences are not usually very well 

 marked, though they are constantly present. Sometimes they 

 are very great, as when, for instance, the progeny of horned 

 parents are hornless, but such variations are of infrequent oc- 

 currence. Some have claimed that in transmission, variations 

 are more constant and greater than resemblances, in other 

 words, the second law of breeding operates more strongly than 

 the first law. In breeding pure bred animals, this is not true. 

 If it were so, the breeder would be on an uncertain sea; with- 

 out sail or rudder. The only improvement that he could make 

 would be through selection. 



