1968, H. Schouteden, Revue de Zoologie Et de Botanique Africaines:
If it is assumed that alcippus is recessive to chrysippus, butterflies classified as weak alcippus in Table V would be heterozygotes with incomplete dominance (matings 2 and 3, females 11 and 13).
1971, Owen, Denis Frank Owen, Tropical Butterflies: The Ecology and Behaviour of Butterflies in the Tropics with Special Reference to African Species, Oxford University Press, USA:
In both localities Danaus chrysippus is not polymorphic, all butterflies belonging to the alcippus form with well ...