MIMICRY, MUTATION AND MENDELISM 



dominant, or heterozygotes respectively. Dubia, in Mr. Lamborn's 

 experience of twelve parents, always gave mixed families. A very 

 striking result was the strong tendency of the dubia offspring in 

 these mixed families to belong to the same form as the female 

 parent. The proportions of the mixed families are sometimes in 

 accordance with Mendelian expectation, sometimes rather strongly 

 opposed to it. The results, as a whole, render it improbable that 

 these exceptions are to be accounted for by the same female 

 pairing with different males. A great difficulty in the way of the 

 usual Mendelian interpretation is the fact that anthedon and the 

 dubia forms predominate at different seasons. Mr. Lamborn has 

 observed this in the field, and it is also shown in the material I have 

 received from him. 



Returning to the above-mentioned four Danaine models of the 

 Lagos district, it would be interesting to know whether Professor 

 Punnett considers all these four Danaine models to be a little self- 

 contained group of the genus Amauris produced by direct mutation 

 within its own limits. Any such assumption would be quite unjusti- 

 fiable. Am. niavius stands quite apart from the others, just as its 

 eastern form, dominicanus, does from echeria ; and among the 

 three other species the resemblance of the form psyttalea (Fig. 4) 

 to hecate (Fig. 5) is purely superficial and no indication of affinity. 

 This statement can be verified even from the reduced figures of the 

 plate. The males of Danaine butterflies almost invariably possess 

 a scent-organ which is believed to be used as an attraction to the 

 opposite sex during courtship. In the genus Amauris this scent- 

 organ takes the form of a double tuft at the extremity of the body 

 and a patch near the anal angle of the wing — the corner opposite 

 to the end of the body. These patches are well shown on the left 

 side of Figs. 2 — 5, and it will be seen at once that both forms of 

 psyttalea (Figs. 3 and 4) have a similar patch, small in size and dead 

 black in appearance, while the distinctly double patch of hecate 

 (Fig. 5) is long and glistening like the shorter one of egialea (Fig. 2), 

 each half of which is seen to be distinctly concave from side to 

 side. No resemblance in the scent-patch accompanies the likeness 

 of the pattern of Fig. 4 to Fig. 5. There is no real approach, but 

 only a misleading superficial resemblance. The objection to these 

 scent-patches as criteria of specific distinction is the fact that they 



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