288 Professor E. B. Poulton on Mimetic Forms of 



(1) P. cenea. S. Africa. Transition to next form in 

 geographical position and morphological character is 

 complete. 



(2) P. tihullus. Delagoa Bay northwards to Mombasa ; 

 west limit unknown, but occurs in Uganda. 



(3) P. 'polytToj)liU8. B. E. Africa. 



(4) Transitional forms from Victoiia Nyanza. 



(5) P. dardaniis dardnnu^. Unyoro to west coast. 

 Congo specimens are larger, as in some other cases. 



Dr. Jordan furthermore states tbat P. dardanus is not 

 sharply marked off into geographical forms. East and 

 west coast examples can be distinguished, but neither 

 assemblage is a complete unit. It is significant that 

 the valve-process is generiilly present in eastern and 

 absent from western forms. 



In the following pages I have followed Dr. Jordan's 

 conclusions and terminok')gy with the single exception 

 that I have called the fifth sub-species dardcmus mcrojJC 

 instead of dardanus dardanus. 



V. Tlic origin of the mimetic female forms of Papilio 

 dardanus /ro7«. the ^ f trimeni. 



There can be little doubt that all the well-known mimetic 

 females of dardanvs as well as the latest discovery 

 planemoides originated by modification of this primitive 

 female form, either directly or by the combination and 

 development of characters on their way to produce other 

 forms. I propose to consider the evolution of these forms 

 in the order of specialization, beginning with the most 

 primitive : — 



(1) Hipijocoon. The relationship of hi'irpocoon to trimeni 

 is at once seen by comparing Fig. 2 with Fig. 1 on Plate 

 XVIII. The transformation is remarkably direct and simple, 

 consisting merely in the greater intensity and sharpness of 

 black markings already distinctly indicated in trimeni, and 

 in the alteration of the pale yellow tint of the latter into 

 white. There are four examples of this form from the 

 Escarpment in the Hope Department. The other three 

 are fairly represented by the figure of the fourth on 

 Plate XVIII, Fig. 2, and it is rather surprising that 

 none of them possess an indication of rudimentary " tails." 

 It cannot be doubted however that hi'jipocoon is by far 



