420 Mr. F. Merrifield and Mr. E. B. Poulton on 



placed with tolerable accuracy, by an examination of the 

 persistent euticular pigment. 



One of these pupte was at the back of the roof in the 

 same bay as those described above. It was chiefly upon 

 tlie black, extending obliquely across parts of two black 

 squares which were in contact at the junction of its 

 anterior and middle thirds ; at this point therefore and 

 on each side it, the sides of the body overhung orange. 

 There was very little pigment and it had been certainly 

 not darker than a (1 y), and probably either a (2) or (3). 



The second pupa was on the roof of the bay at the 

 opposite end of the box, close to the hanging partition. 

 Its anterior half was on black, its posterior on orange, 

 crossing almost at the middle of the adjacent sides of the 

 squares ; its head towards the light. It had probably 

 been a (1 /3). 



Although these five pupas had been subjected to the 

 most strongly contrasted influences in various regions of 

 their bodies, there was not, in a single instance, the 

 faintest trace of parti-coloration. The opposing influences 

 gave rise to a general effect winch was almost exactly 

 intermediate between the effects which they would have 

 respectively produced if they had acted alone. It is to be 

 noted that if there is any deviation from the intermediate 

 position it is in the direction of the effects produced by 

 orange. The larvre seem upon the whole to have rested 

 in contact with black in preference to orange, and thus 

 overhung the latter colour rather more than the former. 

 But many more experiments would be required in order 

 to estimate exactly the relative strengths of these two 

 opposing influences ; and it is noteworthy that the results 

 of my experiments upon this species in 1888 led to dififerent 

 conclusions upon this point. 



The second box was 43'6 cm. x 1 5'4 cm. in internal 

 section and had a depth of 10' cm. It was similarly 

 arranged with G hanging ])artitions, and 7 projecting 

 from the back each 8"5 cm. long but in other respects 

 similar. 



The second box was examined on May 7th. In this 

 case six had pupated on the glass. Of two isolated pupae, 

 fixed in a vertical position with head uppermost, one had 

 emerged and one was dead or emerging ; both were 

 probably (1 y). Two more, similarly placed, were dead 

 and could not be classified. Of two near together, but 



