134 The Inheritance of Wmg-Coloiir in Lei^idoptera 



A consideration of families 1.17 and 22.17 {hazeleighensis x grossulariata) 

 seems to show that the factor I is probably recessive when crossed with 

 the type form, but the fact that there may be more than one modifying 

 factor, no doubt, complicates the case considerably. 



It has already been mentioned that there is a considerable variation 

 in the size of the white collar ofvarleyata (see Plate XIX, figs. 1 — 4 and 

 7 — 10). Not improbably, this variation has been introduced from the 

 dark strain of grossulariata, either by or in association with the factor I. 

 However, the variation is not found to be most highly developed in 

 those families which show the greatest increase of the black pattern. 

 If the restriction of the white collar of varleyata were clearly associated 

 with an extension of the black pattern of grossulariata, it would un- 

 doubtedly behave in the same way. Measurements were made of certain 

 varleyata ^ ^ and $ $ of family '18 G from a cross, F^%y. varleyata ^ . 

 Text-fig. 1 shows the percentage of black on the fore wings of these var- 

 leyata,. This varies between 80 and 100 per cent., and moreover there 

 is a small difference between the black values of the (/ ^ and $ % , 

 amounting to about 4 per cent, in favour of the (/(/, a value which 

 should be above the experimental error, though not of much significance. 



The relationship of the curves for the two sexes may best be seen 

 by reference to Text-fig. 2. It seems possible that even if there were an 

 inhibiting factor associated with femaleness, its effect might be very 

 difficult to measure, on account of the small area of white present in 

 the variety. It was accordingly considered not worth while to under- 

 take a more extensive series of measurements. 



Vars. actinota and leucosticta. 



Another interesting variety of varleyata, which appeared during the 

 experiments, was that showing a varying amount of radiation (Plate XIX, 

 figs. 7, 8 and 9). This variety, which shows a white radiation upon a 

 black ground, must not be confused with var. radiata\ in which the 

 radiation consists of a prolongation of the black marginal spots. The 

 amount of radiation varies from a mere fleck of white on the hind wings, 

 as in Plate XIX, fig. 7, to the striking wedge-shaped markings of fig. 9, 

 which can be seen to extend even to the fore wings. For the first form 

 Mr Raynor has suggested the name var. leucosticta, and for the fully 

 radiated form var. actinota. This character behaves quite independently 

 of the factor L which leads to a restriction of the black pigment. 



1 Onslow, H., Journal of Genetics, Vol. viii. No. 4 (see p. 221, and Plate IX, fig. 56). 



