MIMETIC ASSOCIATIONS 



97 



pattern. Not only is the pale yellow ground-colour of the male represented in a series of 

 scattered markings over both the wings of the left side, but also a portion of the black sub- 

 marginal border of the male hind-wing is plainly visible, as though superimposed on the 

 dark brown portion of the female coloration. Such partially hermaphrodite specimens of 

 various species are by no means unknown in collections, though always extremely rare ; 

 but probably no previous example has even borne such great scientific importance. Even 

 the variety planemoides does not exhaust the known mimetic forms of P. dardanus. In his 

 appendix to the Rev. K. St. A. Rogers's paper on British East African butterflies in the Trans. 

 Ent. Soc, 1908, Trimen has described a form of the subspecies dardanus tibullus, which he 

 has named dorippoides. This specimen is figured on Plate X, Fig 11, and, as will be seen, 

 presents a remarkable resemblance to chrysippus f. dorippus. It would appear to be a modifi- 

 cation from the trophonius form. The single specimen at present known was taken at Nairobi 

 in 1893. Trimen points out that, in view of the tendency of chrysippus mimics to produce 

 modifications towards its form dorippus, we should expect dardanus to have a corresponding 

 form also ; the absence of dorippus from West Africa and its rarity in the south would lead 

 us to expect the appearance of a dorippus-like form in that region where dorippus is known 

 to be common, and this is precisely what has been discovered in the dorippoides variety. 

 No doubt further collecting experience will show that this variety is not so rare as the single 

 example at present available would lead us to suppose. 



Papilio dardanus evidently maintains its existence on the African continent entirely 

 by its very remarkable adaptability to mimetic variation, for even in its larval and pupal 

 stages it presents similar phenomena, the pupa even departing from the usual characteristics 

 of its genus in order to accentuate the deception. In the account of the first breeding 

 experiment already referred to, Mr. Mansel Weale described the early stages of the butterfly.^ 

 The larva feeds on Vepris lanceolaia and in the earlier stages bears filamentous 

 tubercles which probably resemble those of the larva of Amauris echeria. These tubercles 

 grow longer as the larva increases in size up to the last stage, when they become very 

 short, and the full-grown larva is very difficult to distinguish from the leaf. Following 

 on the description referred to, Trimen contributed a paper ^ affording some further 

 details of the early stages, and from these two sources we learn the following interesting 

 particulars. The change from the larva to the pupa is a very singular process and is thus 

 described : The caterpillar generally fixes its anal legs below the axil of a leaf-stalk, and 

 fastens itself below the sixth segment with a double thread to the petiole ; the whole body 

 becomes flaccid and pale green, with an increase of white along the sides, the head curved 

 upwards and inwards. In this state it invariably remains for about twenty-four hours. 

 The body then contracts longitudinally, and the skin is gradually pushed backwards ; when 

 the skin of the head is detached, the bifid tubercles of the head, which in this stage are widely 

 separated, are pointed upwards, and pushed against the suspensory threads ; the antennae,^ 

 which are detached from the rest of the body, are likewise bent upwards, and the united 

 efforts of the tubercles and antennae push the loose skin between the suspensory threads. 

 The body is then violently bent from side to side. The thread by which the anal extremity 

 is attached is lengthened, so that it becomes almost detached, and the loose skin is then 

 shaken off. After a slight pause, the fork of head becomes straightened, and the tubercles 



1 Notes on the Habits of P. merope, with a 

 Description of its Larva and Pupa, J. P. Mansel 

 Weale, Trans. Ent. Soc, 1874, p. 131. 



2 Observations on the Case of Papilio merope, 

 1200 N 



R. Trimen, Trans. Ent. Soc, 1874. 



^ Mr. Weale, in a subsequent communication, 

 expresses some doubt as to whether the antennae or 

 the haustellum may be thus employed. 



