10 



THE VARIATION AND CORRELATIONS OF 



sidering the genus as a whole. Furthermore, the mean lengths of all 

 the organs are smaller in the group having reduced wings than in the 

 long- winged group. 



The Gotha, Florida, collection presents an opportunity to study the 

 biometric relations between long-winged and short-winged groups, all 



the individuals of which had 

 lived in the same environ- 

 ment. Diiferences between 

 an all-long-winged collec- 

 tion, such as the Cuernavaca 

 one (see p. 55), and an all- 

 short-winged one may be 

 correlated with the wing- 

 differences; but, on the other 

 hand, they may be due to dif- 

 ferences in the environment 

 during the growth of the in- 

 dividuals contained in the 

 two collections. However, 

 any significant differences 

 between the two groups of the Gotha collection (see p. 46) must cer- 

 tainly be related in some way to the distinguishing character the wing 

 dimorphism for all the individuals of both groups came from the same 

 field and were collected at the same time. 



TABLE 4. Difference, between the constants of the short-irhif/rd and long-unngcd 



groups from Gotha, Florida. 



12.25 13.25 14.25 15.25 10.25 



FIG. 2. Polygons of frequency for the tegmina at Gotha, 

 Florida. , short-winged group; - , 



long-winged group. 



In table 4 are given the differences between the respective constants 

 of the two groups as shown in table 56. When the constant for the 

 short-winged group is larger than that for the long-winged one, the 

 difference is given as positive; negative in the opposite case. It is 

 apparent that, with respect to the means of all the organs studied, the 

 long-winged group is significantly the larger. This is a conclusion 

 which could not have been reached a priori or from the positive cor- 

 relation noted between the wings and the other organs, as the two 

 groups are not the upper and lower extremes of a continuous range of 

 fluctuation of wing-length. The wing-length seriations, as shown in 



