26 



AFRICAN MIMETIC BUTTERFLIES 



of various convenient surfaces for pupation, but without direct result. As will be gathered 

 from the description of the pupa, it is a very conspicuous object, and it may be concluded 

 that the coloration is, in this stage, as in the perfect insect, aposematic. This remark applies 

 as well, if not better, to the larva. 



Messrs. Marshall and De Niceville, already referred to, describe the three different 

 forms of chrysippus as three species, though there is now no doubt that they are merely 

 varieties. Col. Yerbury (loc. cit.) says, ' I have lumped these four forms together, as, however 

 good species they may be elsewhere, at Aden they are only varieties. I have taken them 

 in coitu in every possible combination, and have reared a considerable number of caterpillars, 

 with the result of having obtained L. chrysippus, intergrades to alcippus, dorippus, and 

 klugii. I could not detect the slightest difference between the larvae that produced these 

 different results. The pupae are dichroic, green and light purple, and are very beautiful, 

 looking as though they had been carved out of the wax tapers used to decorate Christmas- 

 trees.' Also in the same author's notes on this species mentioned by Butler in Proc. Zool. 

 Soc, 1884, part iv : 'I have taken dorippus and chrysippus in coitu so often that I have 

 given up catching them as a curiosity.' 



Butler says that from notes attached to the specimens it would appear that the green 

 chrysalis produced klugii [dorippus), and the purple form chrysippus with intergrades 

 towards alcippus. 



As regards the geographical distribution of D. chrysippus, the type form may be said 

 to extend from Southern Europe to the Cape, and from the Canary Islands to Eastern 

 Asia. The dorippus form does not occur in Mauritius, is comparatively rare in South Africa, 

 and is not found in West Africa. In a collection made by Dr. Wiggins on the Victoria Nyanza, 

 dorippus was the dominating form with 163 individuals against 136 of the type. There 

 were in all 342 examples, and alcippus, alcippoides, and alhinus occurred in the numbers 

 of 18, 16, and 13 respectively. A collection made by Mr. Byatt on the Nyassa-Tanganyika 

 plateau, contained, on the other hand, 288 typical chrysippus and only 8 dorippus. Mr. Lathy, 

 in Trans. Ent. Soc, 1903, p. 184, states that alcippus was the prevalent form in a collection 

 from Anambara Creek on the river Niger in West Africa. In the same volume Dr. Dixey 

 described a collection made by Mr. W. L. S. Loat on the White Nile, and in this region 

 all the varieties occurred together in the same manner in which Col. Yerbury describes 

 them as occurring at Aden. Lieut. -Col. Manders (Trans. Ent. Soc.) records the occurrence 

 of the type form in Bourbon and Mauritius. Generally speaking alcippus may be said to 

 be commonest on the west coast, and dorippus on the east. 



As Col. Yerbury had studied the forms of this butterfly in so favourable a place as 

 Aden, I wrote to him for any facts of interest which he might be able to furnish, and he 

 very kindly replied, giving me his views on the meaning of the different forms. The portion 

 of his letter dealing with the subject is as follows : 'Danais chrysippus in its tetramorphic 

 form appears to have been first established in the countries round the Gulf of Aden (Aden 

 to the White Nile). This tetramorphic form is the ancestral form and has spread from 

 the centre in all directions, the form best suited to its environment being that which has 

 established itself in any particular locality, the other forms only appearing as cases of 

 reversion under unusual circumstances. As regards the four forms of the butterfly, I would 

 divide them into two groups, which I will call the primary and secondary forms of this 

 species. The primary group consists of chrysippus and klugii [dorippus) and these two 

 forms are determined at an early stage by the following conditions. Should the weather 

 be normal after the hatching of the egg, everything will be favourable for the appearance 



