to limitations of the Milllerian Hypothesis of Mimicry. 117 



the clearings rouud the edges of the forest patches ; and 

 when it settles there is no attempt at concealment, but it 

 hangs limply from the end of a leaf or bare twig in the 

 full sunlight. In such circumstances the same colour 

 scheme, which in the Pa2nlio makes for concealment, 

 becomes conspicuous and obtrusive. But it may be asked, 

 if their habits are so different, how can it benefit the 

 Fajnlio to mimic the Plancina ? The question of food- 

 supply furnishes the answer. In the forest itself flowers 

 are few and far between ; they are lovers of sunlight and 

 are to be found principally in the clearings and round the 

 edges of the forest. To such places the Ftqnlio resorts 

 to feed ; it is here that it comes into contact with the 

 Planema; it is here that the forces which make for mimicry 

 find scope to operate. 



There seems reason to believe that the Central and 

 West African Papilios of this group have habits similar to 

 those of echerioides. The group has probably originated 

 in West Africa and spread thence East and South. The 

 larger species, cyi^r^ofila and galliomis, with non-mimetic 

 females, appear to be the least modified members of it, 

 judging by their outline and colouring. The large brown 

 triangle of these species, with its unaltered Papilio 

 streaks, may then represent a scheme of cryptic coloration 

 independently evolved by the group. The roughly 

 Planema-\\ke appearance of this pattern would of itself 

 determine a mimicry of Planema wherever any species of 

 the group came into special contact with that genus. The 

 resemblance would be enhanced by the breaking of the 

 stripes into spots, and by the reduction in size of the 

 brown triangle, so that it would become, as we see it, 

 smaller in the mimetic female than in its non-mimetic 

 male. That this progressive diminution has actually 

 taken place seems to be confirmed by a very interesting 

 form of Papilio cynortct from Uganda, recently described 

 by Mr. Neave under the name peculiaris (Nov. Zool. XI, 

 p. 842, PI. I, f. 7). According to Dr. Jordan (Trans. Eut. 

 Soc. 1906, p. 219, note) the males are hardly distinguish- 

 able from the typical Western cynorta. But whereas the 

 female of that form mimics Planema gea, and has a con- 

 spicuous brown triangle, peculiaris mimics PL paragea, in 

 which the basal triangle is almost obsolete. As a result 

 we find that in the Papilio the triangle has been reduced 

 to very small dimensions, all the stripes have disappeared 



