254 Dr. E. A. Cockayne on 



about the condition of the bursa be a correct one fertilisa- 

 tion does occur in some of these gynandromorphs, though 

 less often than in the case of normal females. 



Since I wrote this I have asked Mr. Bethune-Baker and 

 Dr. Chapman for their opinions. The latter wrote : "As 

 to the dark contents of the bursa I am ignorant, but have 

 supposed it to represent some change (decomposition ? ) 

 in contents after pairing." Mr. Bethune-Baker has noticed 

 its presence, and thinks it is found only after fertilisation.* 



External Appearance. 



The vast majority of the Royston gynandromorphs 

 show the reduction in wing area accompanied by the 

 presence of blue scales, coarse blue hair scales and andro- 

 conia on one side only ; I have seen more than two hundred 

 of these myself. In most specimens the fore-wing appears 

 to be more affected than the hind-wing, but the reverse 

 may be the case. Occasionally only the fore-wing or only 

 the hind-wing may have the abnormal scales, and the 

 other wing on the same side may show a reduction in 

 size or may appear to be exactly like the one on the opposite 

 side (PI. LXVII, fig. 2). In some, coarse hair scales are 

 rare and in others androconia. In some the lunules show 

 no reduction in size. 



The situation of the blue scales is variable, but they are 

 usually most dense on the part furthest from the thorax 

 and distal to the central spot, or along the posterior border 

 in the fore-wing, and in the hind-wing also they are most 

 abundant in situations distal to the central spot. These 

 are just the situations where blue scaling is not found in 

 the blue females, or where it becomes least abundant. 



* In order to throw light on the nature of the brown material 

 in the bursa copulatrix, I dissected in August 1916 three females 

 of A. coridon taken in cop., three virgin females and two gynandro- 

 morphs in very fresh condition. Two of fertilised females had the 

 bursa quite full of brown material, which under the microscope 

 appeared amorphous and granular and was mixed with large 

 numbers of living spermatozoa, the third had very little brown 

 material but spermatozoa were abundant. In the virgin females 

 and gynandromorphs there was no granular brown material and 

 no spermatozoa were present. This makes it almost certain that 

 the brown material is only present after fertilisation, and it is 

 probably the secretion of the glandulae accessoriae of the male. 

 The bursal contents of Ornithoptera helena gave marked Millon and 

 biuret reactions. The two gynandromorphs, ab. roystonensis, showed 

 normal and symmetrical internal and external genital organs. 



