FARMER'S CYCLOPEDIA OF LIVE STOCK 



lay the sexual maturity of cows so that 

 they will not breed until four years of 

 age. But it is not necessary further to 

 multiply examples of the influence of 

 environment on farm animals. It is 

 evident that not all the characters of 

 the adult animal are predetermined at 

 the time of its conception. In other 

 words it is desirable for the breeder to 

 give close heed to the selection of the 

 parents and to the care and feed of the 

 offspring until maturity. 



The influence of the maternal fluids 

 upon the young during pregnancy are 

 apparently of less importance. Such in- 

 fluence, whatever it may be, cannot be 

 determined with any certainty. Ferti- 



and firmly fixed while those of the 

 mother are of a more mixed and inde- 

 terminate nature. On the basis of 

 equal inheritance from both parents 

 Galton formulated his law of ancestral 

 heredity. According to this law the 

 characters of the progeny are determined 

 by the whole line of ancestors, being a 

 mixture of all their tendencies. The im- 

 mediate parents contribute half of the 

 characters and all the other ancestors to- 

 gether contribute the other half, the four 

 grandparents furnishing one-fourth, the 

 eight great-grandparents one-eighth, etc. 

 In other words each parent contributes 

 one-fourth, each grandparent one-six- 

 teenth, etc. 



Fig. 19 — NEAPOLITAN SWINE FORMERLY MUCH USED IN THE IMPROVEMENT OF 

 ENGLISH BREEDS 



lized rabbits' eggs of one breed have been 

 transferred to the oviduct of a female of 

 another breed and at birth show no in- 

 fluence of the latter. 



Equality of parents— All practical 

 experience as well as theoretical consid- 

 erations forces us to conclude that each 

 parent contributes equally to the char- 

 acter of the offspring. There are many 

 apparent exceptions to this statement, 

 but they are more apparent than real. 

 In crossing a thoroughbred male upon 

 a mongrel female the father's charac- 

 teristics may be more conspicuous in 

 the offspring, but this is largely due to 

 the fact that his characters are definite 



Atavism — The phenomenon known as 

 "throwing back," atavism or reversion 

 has always been familiar to farmers and 

 breeders. This consists in a tendency 

 of the characters of the grandparents or 

 earlier ancestors to appear more con- 

 spicuously than is usually the case in 

 the offspring, so that the latter seem 

 to resemble their earlier ancestors 

 rather than their parents. The strik- 

 ing resemblance is sometimes to a 

 grandparent and sometimes to a re- 

 mote ancestor. Darwin accumulated 

 more conspicuous instances of atavism 

 than any other investigator. In one case 

 a dog inherited a peculiar color from 



