The Bionoviics of South African Infiecfs. 293 



B. By E. B. Poulton. 



The following memoir has been written upon and 

 around the great mass of valuable material supplied by 

 Mr. Guy A. K. Marshall's observations, experiments, and 

 captures from 1896 to 1901. So far as this material 

 consists of specimens it is open to the study and criti- 

 cism of all naturalists ; for it has been placed by the 

 generosity of Mr. Marshall in the bionomic series of the Hope 

 Department in the Oxford University Museum. The 

 paper itself has been gradually growing during these years, 

 not only by the accumulation of specimens, but by an 

 uninterrupted correspondence between Mr. Marshall and 

 myself. Extracts from Mr. Marshall's letters form a very 

 important part of the whole work, and it is only right to 

 point out that they were not written for publication, and 

 that any want of co-ordination or continuity is entirely 

 due to this cause. At the time when they were selected 

 and arranged for publication there was no prospect of Mr. 

 Marshall's return to England, and I was anxious that as 

 many naturalists as possible might have the opportunity 

 of reading the observations and discussions from which I 

 had learnt so much and received such great pleasure ; and 

 when eventually he did return the paper had been 

 read. Although no attempt was made to alter or re-write 

 these extracts, Mr. Marshall's presence in England has 

 made an immense difference in the work. We have been 

 able to discuss the general arrangement and illustration as 

 well as the details of many obscure and difficult subjects. 

 On several points he has written paragraphs which give a 

 far higher value to the paper. Where the experience of 

 the naturalist on the spot has been specially required it 

 has become available. The sections of the paper under my 

 own name have also greatly benefited by his kind assist- 

 ance, and the opportunity of discussing points of special 

 difficulty or uncertainty. It will be clear to all who read 

 the paper that Mr. Marshall and I do not entirely agree in 

 the interpretation of many facts, especially those connected 

 with the seasonal phases of Precis, and in the extent and 

 predominance of Miillerian mimicry as compared with 

 Batesian in Lepidoptera. For these and other reasons it 

 is necessary to state explicitly that I am solely responsible 



