xiv ECONOMICAL 167 



Or, again, suppose that a breeder has a chestnut mare 

 and wishes to make certain of a bay foal from her. We 

 know that bay is dominant to chestnut, and that if a 

 homozygous bay stallion is used a bay foal must result. 

 In his choice of a sire, therefore, the breeder must be 

 guided by the previous record of the animal, and select 

 one that has never given anything but bays when put to 

 either bay or chestnut mares. In this way he will assure 

 himself of a bay foal from his chestnut mare, whereas if 

 the record of the sire shows that he has given chestnuts 

 he will be heterozygous, and the chances of his getting a 

 bay or a chestnut out of a chestnut mare are equal. 



It is not impossible that the breeder may be unwilling 

 to test his animals by crossing them with a different breed 

 through fear that their purity may be thereby impaired, 

 and that the influence of the previous cross may show 

 itself in succeeding generations. He might hesitate, for 

 instance, to test his polled cows by crossing them with a 

 horned bull for fear of getting horned calves when the 

 cows were afterwards put to a polled bull of their own 

 breed. The belief in the power of a sire to influence sub- 

 sequent generations, or telegony as it is sometimes called, 

 is not uncommon even to-day. Nevertheless, carefully 

 conducted experiments by more than one competent 

 observer have failed to elicit a single shred of unequiv- 

 ocal evidence in favour of the view. Until we have 

 evidence based upon experiments which are capable of 



