L921. | 



Research in Animal BreedtND. 



1 I 1 



Fig. 3, give reds, roans, and whites in the ratio 1: 2:1. From 

 the view of the practical breeder a roan animal is a hybrid 

 between red and white; the colour cannot be fixed, for there are 

 no " roan " germ cells (only " red " and " white " cells). 

 The breeder who desires roan animals will be well advised to 

 obtain them by crossing red with white ; in this way 100 per 

 cent, of roans will result, as against 50 per cent, from mating 

 roan by roan, roan by red, or roan by white. 



The ' ' breaking up of the type ' ' that often occurs after a cross 

 is a familiar feature to breeders. The first cross animals may 

 show considerable uniformity, though differing from both 

 parental strains. In one character they may take after one 

 parent, in another they may resemble the other parent, while in 

 a third they may be more or less" intermediate between the two. 

 When such animals are bred together a great diversity of forms 

 makes its appearance in the next generation, and in extreme 

 eases scarcely any two beasts may be alike. The skilled breeder, 



Black \^ "Red -p 

 polled ^ horned r ' 



Black 

 -polled 



X 



Black 

 foiled 



B!ack Black "Red. "Red -p 



polled Kovned polled horded 



9 3 3! 



PlG-. 4. — Illustrating the relations of Polled and Honied eattle. 



however, will often name with certainty the original parental 

 breeds of such a mixed progeny, as he will understand that 

 there is something orderly underlying apparent chaos. The 

 breeder who sees as far as this will doubtless welcome the simple 

 explanation that Mendelism affords, but for those who may 

 doubt the possibility of such an explanation, a simple example 

 is given to illustrate the nature of the principle involved. 



Suppose a cross is made between a black polled and a red 

 horned breed. The progeny will be black polled animals (see 



