450 Mr. G. A. K. Marshall on 



H. The attempt to control the Phases of P. sesamus and 

 P, archesia hy the artificial apjjlication of Moisttirc 

 and Heat to the earlier stages. Suggested lines of 

 Experiment. 



All the experiments hitherto made by Mr. Marshall were 

 directed towards the production of the wet natalensis and 

 2)elasgis phases in place of the dry sesamus and archesia 

 respectively. The whole of the specimens produced were 

 presented by Mr. Marshall to the Hope Collection, and all 

 are tabulated below, toiiether with a statement of the 

 experimental conditions which were employed in each 

 case. All experiments were made at Salisbury. 



The following extracts from Mr. Marshall's letters refer 

 to some of the experiments on sesamus: — 



" Salishury, June 5, 1898. — I kept two larvce in a damp 

 jar, but one did not attach itself properly when jDupating, 

 and the resulting pupa fell down when soft and was 

 killed. The other larva produced a black pupa which 

 emerged as the wet form [April 18, 1898, in the Table 

 below], but this was rendered nugatory by the fact that 

 one of the larvae in normal conditions produced the same 

 form, though from a gilded pupa [Aj^ril 20, 1898, in the 

 Table below]." 



" Salisbury, April 25, 1899. — I have fourteen bred 

 specimens of P. sesamus which I will send later [specimens 

 in year 1899 in the Table below]; 1 tried some experi- 

 ments with them, but the results are mostly negative. 

 There are two interesting varieties, one with a red bar in 

 the discoidal cell and another with the red spots much 

 reduced." 



