30 THE OLD ENGLISH SHEEP DOG 



the underlying principle of successful mating towards a 

 definite result. 



But this point once reached, he will have convinced 

 himself that the greater the number of like ancestors, 

 and the closer their likeness to one another, the stronger 

 becomes the probability of reproducing the family charac- 

 teristics. And it is essential to note here that objection- 

 able characteristics are just as surely reproduced as are 

 desirable ones. 



At this stage we come into touch with the phenomenon 

 known as Atavism, which is the tendency of animals to 

 throw back to an ancestor more or less remote, instead of 

 reproducing the characteristics of their immediate parents. 

 And so strange is the working of this factor that an animal 

 may inherit, and transmit to its descendants, qualities and 

 characteristics, good or evil, which will suddenly reappear 

 in some of the members of the family after lying dormant 

 for generations. This tendency is to be noted most care- 

 fully, and its influence for evil to be perpetually borne in 

 mind and continually guarded against. 



Having thoroughly grasped these primary essentials, 

 and satisfied himself of the necessity for a most careful 

 study of ancestry and family characteristics, the beginner 

 may go on to consider the workings of Natural Variability. 

 In its broad sense this may best be understood by 

 remembering that no two puppies or, for that matter, no 

 two children born of the same parents are in every 

 respect identical either in character or appearance. 



