WARNING COLOURS AND MIMICRY 157 



phical range of H. misippus is very similar to that of the 

 Danaine butterflies, and wherever a change of coloration 

 occurs in the latter, it is invariably reproduced by the 

 mimicking females of the former. The three chief forms 

 of the model and its mimic are shown, but there are 

 numerous intermediate varieties. Nevertheless, while the 

 females invariably follow the lead set by the distasteful 

 model in different localities, the colouring of the male is 

 always the same. It is interesting to note that Mr. 

 Frank Finn, when in India, proved by experiment that 

 H. misippus is liked by birds which will not touch the 

 malodorous Limnas. 



In the case of H. misippus Nature has obliterated 

 every trace of the manner in which she achieved this 

 triumph of deception. No intermediate stages remain to 

 connect the mimetic colouring of the females with the 

 ancestral colouring of the males. But a closely allied 

 butterfly, called H. bolina, supplies a kind of key to the 

 mystery. This insect is not found in Africa, but it is 

 common in the Indian region, where it exists side by side 

 with H. misippus. The males of the two species are 

 practically identical in coloration, but the females of 

 H. bolina vary in a most erratic manner. Some are almost 

 like their mates, others look like half-finished copies of 

 common evil-tasting types, while the majority are bare- 

 faced "sports." Many of them, however, are excep- 

 tionally interesting to the student of evolution because 

 they show a gradual increase of tawny colouring from a 

 small spot to a large suffusion of the wing-area. Such 

 specimens go far to bridge over the gap which exists 

 between the black-and-white males of H. misippus and 

 their mimetic, tawny females. They do not, indeed, 

 supply us with a full and complete solution of the evolu- 

 tionary problem which is involved ; but such a series of 



