MIMICRY, MUTATION AND MENDELISM 



carry out in a tropical station, seventy miles from Lagos, but Mr. 

 Lamborn was able to maintain a temperature of about 50° F. for 

 rather over three days. Four out of the fourteen resulting females 

 possessed rudimentary " tails," so it is probable that some effect was 

 produced by the shock. The trimeni female also occurs, although 

 very rarely, on the East coast, and an ancestral form resembling it 

 in the imperfect bar crossing the fore wing has long been known as 

 dionysus on the West coast, where it is very rare as compared with 

 hippocoon. The Kikuyu Escarpment is the only locality at present 

 known where these transitional forms make up a large proportion of 

 the females. Side by side with them the fully developed hippocoon 

 (Fig. 8) occurs together with all the other forms, including planemoides. 

 This locality is also unique in the numbers of unnamed varieties and 

 transitional forms. The origin of trophonius (Plate I., Fig. 8) is 

 well seen in the form shown in Plate II., Fig. 9 — a trimeni female 

 with yellowish markings and even a slight trace of the " tail," 

 but with the great patch extending over a large part of both 

 wings almost entirely overspread with a fulvous flush. The cenea 

 female — the most specialised of all — was also probably evolved 

 from trimeni ; for the specimen represented on Plate II., Fig. 4, 

 although possessing the fully developed pattern (compare Fig. 5, as 

 also Plate I., Figs. 9 and 10), still retains the ancestral pale yellow 

 markings. Furthermore, most of the markings in the fore 

 wing are recognisable, although with indistinct outlines, in the 

 fore wing of some examples of trimeni (compare Figs. 4 and 6 on 

 Plate II). 



The planemoides form probably arose in association with the 

 origin of cenea, the hind wing patch becoming white, while the 

 reduced pale markings of the trimeni fore wing, instead of concen- 

 trating into spots, broke through the black bar and, gaining a rich 

 fulvous tint, fused into a broad band crossing the wing. A single 

 example of planemoides obtained by the Rev. St. Aubyn Rogers in 

 the Mombasa district, hundreds of miles east of its Planema models, 

 exhibits ancestral features in the tendency of the fulvous band to 

 divide along the line of the original black bar. In the leighi form 

 which has occurred several times in Natal — twice in a single family 

 as described on p. 44 — and thus at an immense distance from the 

 tropical model, we meet with another still more ancestral stage of 



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