MUTATIONS 



337 



cell became separated from the body cells, investigators are 

 having difficulty in explaining how the germ cells can transmit 

 the acquired characters. 



However, a plant or animal will often appear, which, from the 

 first, is so unlike its parents that it is called a freak or sport. For 

 example, albino animals which have no pigmentation in fur, skin, or 

 eyes are not infrequent. White rats have been developed as a 

 distinct species from a sport which appeared as an offspring of 

 rats with pigmented coats. Albinism is inherited as a recessive 

 trait and is sometimes found in humans as well as other animals. 

 This sudden departure from the ancestral type is called a mutation 

 and the individual itself is a mutant provided the new species 



Hugo de Vries bred evening primroses through numerous generations. As his experiment 

 progressed, he observed among them peculiar dwarfed individuals which bred true. He called 

 these nanella- Then he isolated a type with unusually broad leaves which he called lata, and a 

 type with reddish veins, the rubrinervis. In successive generations, he observed other plants 

 with different characteristics. He preserved the new qualities by careful breeding. These 

 were mutant primroses. 



