The Bionomics of South African Insects. 483 



indications of the white sub-apical bar of chrysippns can 

 be detected in khigii, especially at the points on the costa 

 and the hind margin which the two ends of the bar would 

 have reached. Very faint traces of the course of tlie bar 

 between these two points can be made out in certain 

 individuals (Plate XV, fig. 1), while occasionally they are 

 very distinct, especially upon the under-side (Plate XV, 

 fig. la). Looking at these two figures, and comparing 

 them with Figs. 1 and la on Plate XIV, it is impossible 

 to resist the conclusion that we see before us the vestiges 

 of a fading character and not the rudiments of a developing 

 one. It is interesting to note that one of the slightly 

 intermediate varieties oHdugii here represented (viz. Fig. 1, 

 Plate XV) was an individual captured by Mr. and Mrs. 

 Hinde at Machakos Road, and that three or four others of 

 the same set showed similar tendencies. It may be that 

 the unfavourable conditions (see pp. 478, 474), although 

 unable to change one form into another, nevertheless 

 administered a shock which caused a slight reversion 

 towards the ancestial type in some individuals. 



The three great mimics of both forms of chrysippus, the 

 female of the Nymphaline, Hypolimnas niisippus with its 

 inaria form mimicking Ixingii ; the Acrseine, A, encedon * 

 with its I'hirjii -like form daira ; the Lycosnid Mimacriea 

 marshalli with what I believe to be merely its llugii-\\V.e 

 form dolurtyi, all these show precisely the same thing as 

 their model only in an exaggerated form, because the 

 xi\\m\Q follows its model and therefore still exhibits stages 

 which the latter has left behind. Comparing the upper- 

 and under-side of the clirysippiis-Yike Lycsenid on Plate 

 XIV (Figs. 2 and la) with those of the ldugr[-X\k^ form 

 on Plate XV (Figs. 2 and 2ft), there can be no doubt 

 that the latter developed from the former. The white 

 bar of niarshcdli (Plate XIV) can still be distinctl}^ 

 traced in dolicrtyi (Plate XV), not indeed as a white 

 bar but as a very faint paling of the ground-colour 

 over a sub-apical area, the outline of which exactly 



* Tlie first recognition of the mimicry of chrysipinis by encedon, 

 and indeed of the existence of Miillerian mimicry in the Ethiopian 

 Region, was first brought forward at the meeting of the British 

 Association at Toronto in 1897 (Report, p. 689). Aurivillius (Rhop. 

 Eth. 1898, p. 533) states that the resemblance liad not been previously 

 noticed. The account given by Aurivillius is however far more com- 

 plete than that in the brief abstract here referred to, and is also 

 accompanieil by illustrations. 



