30 



MENDELISM 



the half of a walnut, is a type of comb which is 

 normally characteristic of the Malay fowl. Moreover, 

 when these F^ birds were bred together, a further 

 unlooked-for result was obtained. As was expected. 



Fig. 4. 



Fowls' combs. A, pea ; B, rose ; C, single ; D, walnut. 



there appeared in the F^ generation the three forms 

 walnut, rose, and pea. But there also appeared 

 a definite proportion of single combed birds, and 

 among many hundreds of chickens bred in this way 

 the proportions in which the four forms walnut, rose, 

 pea, and single appeared was 9:3:3: i. Now this. 



