Other Kinds of Hybridizing 



161 



forms, one with the other without horns. There is a large and a 

 small form of earwig. Papilio glaucus has two forms of females, 

 one yellow, the other black. The latter is found over the south- 

 ern range of the species. "In this region both yellow and black 

 forms have been reared from eggs produced by a single female." 



FIG. 17. 



A number of cases are known in the higher plants, and their 

 inheritance has been examined in a few instances. These are all 

 hermaphroditic forms in which two kinds of flowers both pro- 

 ducing ova and pollen are present on the same or on different 

 plants. The European cowslip, Primula veris, occurs in two 

 forms, the long-styled and the short-styled (Fig. 17). Each 

 plant bears flowers that belong to one type only ; the two types 



