IntersexuoJ forms of Plebeiits argns L. 233 



In two specimens tlie whole bursa was very small and 

 narrow, both the tubular part and the caput, and in 

 another the tube was long and wide and the caput short 

 and broad (Plate I, fig. 8). One had a constriction of the 

 ca])ut as well as a dilatation of the proximal part of the 

 tubular portion. 



My figures, which are drawn to scale, show these abnor- 

 malities and also the great variation in the total length 

 of the tubular part and in the size of the caput. A 

 shrunken wrinkled caput is probably normal, and merely 

 indicates loss of contents and contraction of the muscle 

 within. The caput has a single layer of cubical epithelium 

 covering the thick chitin, on the inner side of which 

 numerous tracheae run. Inside this is a thick layer of 

 circular muscle fibres. 



Four intersexes had a transparent caput and were 

 probably virgins. In many it contained some opaque 

 yellow material like that found in worn normal females. 

 These had probably been impregnated some days before. 

 In several it was full of dense white and brown contents 

 such as I have found in argvs and coridon taken in cop. 

 These had been impregnated recently. Amongst the con- 

 trols two had bursae with a shrivelled, square-ended caput 

 and a narrow tubular part dilating about half-way down 

 into a wider tube. Two others with abnormal dilatations 

 are figured (Plate IX, figs. 1 and 2). 



The bursae were examined in most cases immediately 

 after death, and rough sketches made, which agreed closely 

 with the more careful drawings made after preservation 

 in alcohol. 



Comparison of the Genitalia of Intersexes of 

 argus and coridon. 



The intersexes of argvs agree with similar specimens 

 of coridon in having normal female external genitalia. 

 Amongst the coridon one with small cement glands and 

 one with a bursa constricted between tube and caput Avere 

 found like some of the abnormal argus. In both species 

 a specimen was met with which had only three egg-tubes 

 in each ovary instead of four. But no coridon was found 

 with abnormal ova in the ovaries hke the two argus, 

 and no argus was found with complete absence of bursa 

 and ductus bursae, or with a bifid termination to the 

 spermatheca, which were abnormalities found in coridon. 



