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Mendel found that in cross-breeding between alternative characters, 

 one uniformly dominates in the offspring from its very nature, while 

 the other disappears. Just as, when the two pieces of glass are held 

 up together Ave see only the opaque one, the transparent one being 

 invisible. Mendel called the character seen in the offspring dominant, 

 the unseen one he called recessive. In rabbits, the gray pigmented or 

 Belgian hare coat is dominant over the albino coat, the latter being 

 recessive (unseen) in cross-bred animals. Similarly, in mice, guinea- 

 pigs, and even in man, mating of an albino with a pure, pigmented 

 individual produces only pigmented offspring. In guinea-pigs the 

 rosetted or rough coat is dominant over smooth (normal) coat (see 



Fig. 5. A Guinea-pig with Short, Smooth, Pigmented Coat. 



Fig. 6) ; and short coat is dominant over long (or angora) coat (Fig. 

 8). In rabbits, also, the normal or short coat dominates over the 

 angora coat (Fig. 3), and the same is probably true in cats and goats 

 as well. 



Among guinea-pigs there occurs a series of alternative pigment 

 types which show Mendelian relations one to another. If we write 

 them in this order, (1) agouti (i. e., black ticked with yellow, the 

 ancestral or wild type of coat), (2) black, (3) yellow, (4) albino, 

 we may say that each is dominant over all which follow it, and re- 

 cessive in relation to all which precede it. Thus agouti mated with 

 black, yellow or albino gives only agouti offspring; black mated with 

 yellow or albino gives either black or agouti, but never yellow or albino, 

 while yellow dominates over the albino only. In man, a condition of 



