13^ EVOLUTION 



It is interesting now to inquire into the 

 occurrence of this remarkable mode of in- 

 heritance, which is seen when the parent 

 forms have opposite or contrasted characters 

 which do not blend. The striking fact is the 

 diversity of the organisms in which it has 

 been demonstrated in the short period since 

 1900, e.g. in mice, rats, rabbits, guinea-pigs, 

 cattle, poultry, canaries, snails, silk-moths; 

 in beans, maize, wheat, barley, stocks. 

 Another striking fact is the great variety of 

 characters to which it applies, e.g. shades of 

 colour, peculiarities of fur and feathers, 

 abnormal features like extra toes, subtle 

 qualities like "broodiness" in hens, early 

 ripening or immunity to rust in wheat, and 

 so on. 



Let us give a few examples, arranged in 

 parallel columns. 



Animals 



Dominant character. Recessive character. 



Hornlessness in cattle. Presence of horns. 



Normal short hair in Long "Angora" 



rabbits and guinea- hair. 



pigs 



Short tail in Manx cat Normal length of 



(somewhat imper- tail. 



f ectly) . 



Normal movements in Waltzing in mice. 



mice. 



