180 Plant-Breeding 



commercial types are self-fertilized, they produce progeny 

 in the approximate ratio of 1 single : 2 commercial doubles : 

 1 dpuble-double or bull-head (Fig. 45). 



FIG. 45. Hybrid carnation (center) between a single and a burster, 

 showing intermediacy. 



The hybrids between a large, apple-shaped tomato 

 and a small, pear-shaped one are intermediate between 

 the parents in the first generation, as has already been 

 noted. In all probability there are represented in the 

 above characters more than one unit. Emerson has 

 made similar observations in beans, gourds, and maize, 

 Locke in maize, and Castle in rabbits. 



"While it is not uncommon," says Spillman, "for a 

 character to be dominant or recessive in a cross, it is 

 seldom that dominance is absolute. The presence of the 

 recessive characters can easily be detected, and in some 

 cases very easily. Thus in the cross between bearded 



