STUDIES OF VARIATION IN INSECTS 



305 



Looking to the correlation of the number of spines in outer 

 and inner row of same leg, in outer rows of right and left legs 

 of same individual, and in inner rows of right and left legs of 

 same individual the followincr conditions obtain in our series : 



Fig. 68. Frequency polygon of the variation in number of spines in inner 

 row of right tibize of 48 female red-legged locusts, Melanoplus fe7nur-r7ibrum. 



In outer and inner rows of right tibiae : in males (39) numbers 

 were the same in 15 cases, numbers differed by one in 19 cases, 

 numbers differed by two in 3 cases, numbers differed by three 

 in 2 cases ; in females (50) numbers were the same in 17 cases, 



Fig. 69. Frequency polygon of the variation in number of spines in inner 

 row of left tibia; of 47 female red-legged locusts, Melanoplus femtir-rubriim. 



numbers differed by one in 22 cases, numbers differed by two 

 in 8 cases, numbers differed by three in 2 cases. 



In outer and inner rows of left tibice : in males (39) numbers 

 were the same in 19 cases, numbers differed by one in 13 cases, 



