( XX ) 



in the above list. This great disproportion between the sexes 

 rendered it probable that all-female families of encedon would 

 be found in Natal; for Mr. Lamborn had found that these 

 families in the Lagos district were compensated by families 

 in which the males were more numerous (Journ. Linn. Soc, 

 Zool., xxxii, 1914, p. 400). 



Judging by the 52 specimens exhibited to the meeting, 

 the whole of the 228 offspring were sharply divided into the 

 two forms that w^ere commonest in Natal — (1) encedon, 

 generally with a bright fulvous ground-colour, occasionally 

 darker and approaching infuscata, Auriv., the females with 

 white, the males with yellow subapical bar to the fore-wing; 

 (2) forms resembling the dusky yellow variety of the white 

 lycia, F., named sganzini by Boisduval; the females much 

 paler and therefore nearer to lycia, F., than the males. 

 The Mendelian relationship, although probable, was not very 

 clear in the proportions — 139 encedon, to 89 sganzini. There 

 was little doubt, from Mr. Lamborn's experiments, that, in 

 the Lagos district, encedon was dominant and lycia recessive. 

 It was therefore likely that the same relationship held in Natal, 

 lycia being represented by the yellowish sganzini. If this 

 were so, it was probable that the female parent was a hetero- 

 zygote which had mated with a recessive [sganzini) male, 

 and that the results are to be explained as a very imperfect 

 approach to equality. More breeding experiments were 

 needed in Natal, to test the Mendelian relationship and the 

 existence of all-female families. 



Although the two forms segregated so completely there 

 was marked individual variation in both of them. This was 

 especially well seen in area 2 of the fore-wing in the great 

 majority of the examples of encedon, both male and female. 

 Here a triangular white spot was developed on the outer 

 (distal) side of the black spot that is a characteristic feature 

 of this area. A beautifully gradual transition was manifest 

 in both sexes, passing from maximum development to entire 

 disappearance of this white spot; and a similar gradation 

 was seen in the sganzini forms in which, however, the feature 

 was far less striking, because in these the spot was of the same 

 tint as the ground-colour of the wing. 



