EARLY EVIDENCE OF CONSPECIFITY 255 



resemblance to different species of West African Planemti. 

 (See Dr. Jordan's paper, already cited.) 



It will be interesting now to trace the development 

 of our knowledge of this most fascinating polymorphic 

 species. 



Professor Poulton, in a letter to Nature, August 28, 

 1912, stated : "A little more than two years ago Dr. 

 Karl Jordan informed me that he had been studying 

 the male genital armature of the Pseudacraeas, and that 

 he could not find any difference between the ' species * 

 of a large group made up of Linne's eurytus and its 

 numerous allies on the West Coast, of Neave's hobleyi 

 terra and obscura in Uganda, of Trimen's rogersi of the 

 Mombasa district and his imitator of Natal." 



The provisional conclusion drawn from this fact was 

 that these butterflies are conspecific, and this was brought 

 before the first International Congress of Entomology 

 at Brussels by Dr. Jordan in August 1910. 



At the same congress Professor Poulton gave a statis- 

 tical study of the large collection made near Entebbe in 

 Uganda by Dr. C. A. Wiggins, and stated that in this 

 were two specimens which tended to confirm Jordan's 

 anatomical findings. One was " a male Ps. terra with 

 a pattern approaching the male of Ps. hobleyi,'^ the 

 other " a female Ps. hobleyi bearing the mimetic colours 

 of its own male " (this is the form now known as 

 foggeoides). (Plate I, fig. 10.) 



Quotations from letters that I received from Professor 

 Poulton after work was commenced on the islands in 1911 

 will show how keenly interested he was in the problem, 

 and how important he considered it. 



I first met with Psevdacraea eurytus on Damba Island 

 in 1911, towards the end of my stay there, and, not know- 

 ing anything about it, found this mimetic butterfly very 

 puzzling. Not only was it difficult at first to distinguish 

 the forms from their models, but they showed such varia- 



