BEDROCK 



the planemoides female in which the fulvous band is represented by 

 three widely separated patches corresponding in position and form 

 with the two chief costal markings of hippocoon or trophonius and 

 the largest oval marking in cenea. It is impossible to interpret 

 leighi as a hybrid between one of the other female forms and plane- 

 moides, because the latter is entirely unknown in Natal and indeed 

 far to the north of it. 



Further important evidence in favour of the gradual building up 

 of the mimetic forms is furnished by a careful study of the thirteen 

 families of known parentage in the Hope Collection. We thus 

 learn that small features in the pattern of the parent certainly tend 

 to reappear in her offspring. I have traced this in three markings 

 or sets of markings, but will here confine myself to one. It has been 

 pointed out that the principal marking of the hippocoon female of 

 the east (Plate I., Fig. 7 ; Plate II., Fig. 8) is very large, like that of 

 its model (Plate I., Fig. 2), but that the same marking is much 

 smaller in the west, corresponding with that of the western Danaine 

 (Plate III., Fig. 1). Now Mr. Lamborn's western families of hippo- 

 coon females exhibit marked differences in the size of the marking, 

 so that the majority of the females of one family are a small but 

 distinct step nearer to the hippocoon of the east than is any one of 

 the females of another family. Hereditary material exists which, 

 given selection, could easily produce the eastern from the western 

 mimic, or vice versa. Furthermore, transitional forms are common 

 near the zone where the one model passes into the other. It is 

 difficult to see how the evidence of an evolution by gradual steps 

 could be stronger than it is. 



The second example is not quite so complex, and it affords a very 

 interesting comparison with dardanus, inasmuch as both males and 

 females are mimetic. The important Oriental and Ethiopian genus 

 Hypolimnas belongs to the Nymphalince, — the great group of butter- 

 flies which includes our English Purple Emperor, White Admiral, 

 and Vanessa and its allies, including the Red Admiral, the Peacock, 

 the Tortoiseshells and the Comma. Hypolimnas is nearly related 

 to these butterflies, and the chrysalis of the species we are considering 

 (H. dubia and anthedon) closely resembles that of our common 

 Vanessids. The larva too is black and spine-covered, and feeds on 

 a kind of nettle (Fleurya), like many Vanessas. Nearly the whole 



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