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AFRICAN MIMETIC BUTTERFLIES 



parallel. The body is at intervals drawn up at the thorax ; the head is drawn downwards 

 and the antennae become attached to the body. The anal extremity is again attached. 

 The keel and lateral ridges appear, and the bifid processes, which are now closely parallel, 

 are bent downwards. The imago emerges in about three weeks.' Remarking on the very 

 curious and exceptional function of the cephalic processes and the haustellum or antennae, 

 Trimen points out the interesting fact that those organs which perform the function of con- 

 version to the pupal stage are just those which afterwards contribute so much to the cryptic 

 nature of the pupa. The haustellum represents the midrib of the leaf and the processes 

 the apex. The pupa is so perfectly adapted to resemble the leaves amongst which it is 

 found that it is only with the very greatest difficulty that it can be seen. It is much flattened 

 and the lateral ridges are greatly developed. The ventral side is darker than the dorsal, 

 though as it is placed with the ventral side uppermost it thus perfectly represents the lanceo- 

 late leaf, which is darker above than below. The cephalic processes, usually wide apart in 

 pupae of this genus, are in this case contiguous, and represent the point of the leaf. So 

 perfect is the resemblance that the same author records that even when attached to a bare 

 mimosa twig it deceived several persons to whom he exhibited it. Mr. Leigh says^ that the 

 larvae feed on the lower parts of the plant, and though not so difficult to detect in the earlier 

 stages, they are in the last stage ' the hardest larvae to find of any with which I am acquainted 

 . . . the pupae are even harder to find than the larvae'. The same naturalist also furnishes 

 the interesting information that the pupa of the trophonius form is distinguished by a number 

 of brown lateral markings. 



Whilst the female dardanus has adopted a variety of forms of disguise in order to 

 escape her enemies, the male has to rely on his superior powers of flight. The female adopts 

 the slow-flying habits of its models, and frequents the thick bush, whilst the male is found 

 more in the open and is a strong and rapid flyer. As Mr. Weale remarks, ' nothing can be 

 more remarkable than the difference of flight in the two sexes.' Physical activity would not, 

 however, serve to protect the insect when at rest, and it is interesting to learn that it reverts 

 to the subterfuges of its earlier stages and becomes extremely cryptic. The somewhat 

 elaborate pattern of the underside as shown in Fig. 2 would not perhaps at first sight suggest 

 invisibility, but when settled with the fore-wings dropped back within the secondaries, and 

 the longitudinal markings accentuated by the tail, the insect becomes extremely difficult 

 to observe. Thus, in a letter to Trimen ^ in 1871, Mrs. Barber wrote as follows : ' I caught 

 a fine merope with my finger and thumb the other day. It was just beginning to rain, 

 and, though it was not late, merope thought proper to seek a resting-place, which he wisely 

 chose upon a shrub which resembled his own underside colouring. It was a splendid match : 

 when he closed his wings amongst the yellow and brown seeds and flowers of the shrub, 

 no bird would ever have distinguished him. I had no net with me, and my first attempt 

 was a failure. However, the butterfly took a turn round the neighbourhood, examined 

 several other shrubs (which he found not so good I suppose) and eventually returned to the 

 same perch.' Surgeon-Capt. W. G. Clements, writing ' On a Collection of Sierra Leone 

 Lepidoptera ', 1893, notes a similar habit in the male of typical P. dardanus. He states, 

 * It almost invariably selects a broad-bladed grass, striped with brown and yellow, and 

 hanging pendant from its extremity with the wings folded, the upper ones being covered 

 over and concealed by the lower, it cannot be seen until it is again startled into flight.' It 

 may be noted that Mr. Weale has observed a species of flycatcher chase and capture P. merope, 

 as he records in the paper already referred to. 



^ Trans. Ent. Soc, 1904, p. 679. 2 Trans. Ent. Soc, 1874, p. 145. 



