246 Dr. E. A. Cockayne on 



whole day or more examining thousands of females and 

 not find a single gynandromorph, and then one may find 

 two or three close together in a very short time. 



This fact has been noticed by Mr. Newman and Mr. 

 Pickett, both of whom have collected very extensively 

 at Royston, and by other Entomologists. My own ex- 

 perience strongly supports the view that several may 

 occur in one family. 



In 1914, one evening when coridon was beginning to 

 settle down for the night, I found two on neighbouring 

 plants of knapweed, and two others only a few yards 

 away. All four were very perfect and probably had 

 emerged quite recently. 



Last year I had a still more striking experience. I 

 went to the locality too early in the season and found 

 that coridon was scarce and that few females had emerged. 

 Mr. Newman told me that in three days he had not captured 

 a single gynandromorph. Yet on July 25th, in one small, 

 rather isolated piece of ground, where not more than fifty 

 females were flying, I took five gynandromorphs, and a 

 sixth specimen with the wings smaller on one side but 

 without any blue scaling. All these had emerged quite 

 recently, and none had ova descending the oviducts. Two 

 other gynandromorphs were taken elsewhere on the downs. 

 On July 28th I took a specimen with one side small and 

 with two blue scales and a coarse hair scale on the small 

 side on the same bit of ground, and on August 1st took 

 four more gynandromorphs and another female with the 

 wings unequal, but with only two blue scales on the small 

 side, all on exactly the same spot. Prolonged search 

 elsewhere only yielded two more. All the ones taken close 

 together were very freshly emerged, and were probably 

 members of a single family. 



In describing the internal and external organs in this 

 species I have continued to use the names adopted in my 

 earliest papers. Dr. Chapman, however, has very kindly 

 written to me and told me that he considers the organ I 

 have named the caput bursae to be the entire bursa copu- 

 latrix, and that what I call the bursa cojndatrix is nothing 

 more than a specialised chitinous arrangement for ex- 

 truding the long tubular prop or hypostema with its 

 chitinous genital opening. He names this the rein or 

 henia. His views are probably correct. But the subject 

 is a difficult one, as it is uncertain what structures in 



