THEORY OF EVOLUTION 



81 



It has been found that there may be even 

 more than two factors that show Mendelian 

 segregation when brought together in pairs. 

 For example, in the southern States there are 

 several races of the grouse locust (Paratettix) 



'LACTICOLOK ? 



GTOS5ULARIATA d 1 



FIG. 42. Reciprocal of Fig. 41. 



