208 



The Mechanism of EvoLUTioisr in Leptinotaesa 



Table 25. — Observed frequency of occurrence of the different types of variation in 

 spot c in each of the colonies during ten successive " generations." 



Basoco Colony: 



June, 1904 



August, 1904 



June, 1905 



August, 1905 



July, 1906 



September, 1906 



July, 1907 



August, 1907 



June, 1908 



August, 1908 



Quauhtemotzin Colony 



June, 1904 



August, 1904 



June, 1905 



August, 1905 



July, 1906 



September, 1906 



July, 1907 



August, 1907 



June, 1908 



August, 1908 



San Antonio Colony: 



June, 1904 



August, 1904 



June, 1905 



August, 1905 



July, 1906 



September, 1906 . . . 



July, 1907 



August, 1907 



June, 1908 



August, 1908 



Observed shape and direction of spot c. 



Absent . Small. Large 



c-^d. 



c + d. 



c->-e. 



If 



17 

 24 

 51 

 106 

 77 

 15 

 49 

 74 

 10 

 92 



142 



171 

 86 



105 

 88 

 21 

 55 

 71 

 45 



109 



71 

 121 

 59 

 50 

 92 

 46 

 31 

 100 

 18 

 77 



:ii 



4 



7 



3 



14 



2 

 17 

 4 

 7 

 9 

 17 



2 

 3 



2 



