794 REPORT— 1900. 



that the observation was made at Salisbury, JIashonaland (5,0C0 feet). The 

 observations here briefly recorded have added in a most important manner to our 

 knowledge of the natural history (bionomics) of South African insects, a subject of 

 which the foundations were laid by Roland Trimen. Groups of mimetic Lepido- 

 ptera captured on the same day as their models have been obtained both from Natal 

 and Mashonaland (Salisbury), thus demonstrating more fully than has been done 

 hitherto the fact that model and mimic fly at the same time as well as in the same 

 place. The groups bring out the extraordinary power of Danaine butterflies in, so 

 to speak, moulding the species of other sub-families into a superficial likeness to 

 themselves. There are only four or five species of Danmna in the region under 

 consideration, and each one of them is the centre of a group of forms superficially 

 similar, but remote in affinity. The abundant and widespread Limnas c/in/sippus 

 was largely resembled both in Natal and Mashonaland. In experiments conducted 

 upon insect-eating animals, this butterfly appeared to be less unpalatable than the 

 Acrcca (A. encedon) which resembles it. The explanation may be found in the far 

 wider range of the Danaine model, which would render it familiar to enemies 

 passing from an area in which the Acrcea does not, to one in which it does exist. 



In the case of two forms of Eiiralia (E. mima and E. ica/ilben/i) mimicking two 

 very different species of Ammiris {A. echevia and A. dominicanus) there is good 

 reason to believe that a single species has become dimorphic. Photographs of 

 four mima (two male, two female) and four icahlbergi (three male, one female) were 

 shown, the whole set having been part of a company of twelve individuals going to 

 rest together on a small clump of fern under a steep kraantz, Umbilo Eiver, 

 Malvern, near Durban, Natal (June 28, 1897). The two forms have also been 

 taken in coihi, and have been found together freshly emerged from the pupa on the 

 same tree. Intermediate varieties are also known. If specific identity be established, 

 the case will constitute a new form of mimetic dimorphism in the Lepidoptera, 

 similar to that of the Dipterous genus Volucella. All cases of dimorphism in mimetic 

 Lepidoptera hitherto described are either sexual or confined to a single sex. In one 

 sex, indeed, a mimetic species may be polymorphic, as in the female of Papilio 

 certea or Hypolimnas inisippus. 



In the case of tlie distasteful sub-family AcrmntE, the two very different 

 species A. natalica and A. anemosa were shown captured at Salisbury on the same 

 day. Although entirely different in detail, the pattern of the two species is broadly 

 the same, and during flight would probably appear to be identical. Another even 

 more striking example of Miillerian or synaposematic resemblance was aff'orded by 

 a set of eighteen specimens belonging to five species of small Acrreas captured on 

 the same day (December 31, 1898) in the same locality. The whole group pre- 

 sented a wonderfully uniform appearance in size, shape, colour, and the general 

 distribution of markings. 



An example of a Hesperid (Baoris netophn) mimic of an Acr(pa {A. doubie- 

 dayi), the two captured on the same day, added another to the rare instances of 

 mimicry in this family. The resemblance is onlj' seen in the attitude of rest, 

 and is confined to the undersides of the wings. 



The aberrant Lycrenid {Alcrno amazoula) has a general Acrreine aspect, and 

 is very unlike the Avell-known appearance of its true family. It is probably dis- 

 tasteful, and is resembled with tolerable closeness, especially upon the under- 

 sides of the wings, by a day-flying Geometrid moth (Peiovia dichroaria). They 

 were captured together at Malvern, near Durban, on September 26, 1897. 



A most interesting series of injured specimens of butterflies showed the 

 probable attacks of birds or lizards, observations in the field aflxjrding strong sup- 

 port to this interpretation. Members of the specially protected conspicuous 

 groups were, as Fritz Miiller showed in the case of South America, also subject to 

 attack. Comparatively few of the injuries were inflicted at the junction of the 

 fore and hind wings, or indeed anywhere except at the apex of the fore wing, or, 

 more commonly still, at the anal angle of the hind wing. In many cases the 

 injury was symmetrical, indicating that a piece had been bitten out of both right 

 and left wings during the usual attitude of rest, or as they came together momen- 

 tarily in flight. The two points of special attack are commonly rendered con- 



