78 " Gi/uandrotuorphisni" (iiid Kindred Problems 



Group IV. Mixed Gynandromorphism. 

 (Lateral, transversal and frontal intermixed.) 



1. Left (/• 5- Dorsally (/. 



2. Left $. 6. Dorsally ?. 



3. Anteriorly c/- '''• Decussating. 



4. Anteriorly ? . 



Nearly all gynandromorphs fall into the fourth group. 



The floi-so-ventral arrangement of the external characters has been 

 met with once, and the antero-posterior rather more frequently. I have 

 seen two specimens of Satumia carpini with a male head and antennae, 

 the rest of the insect being female, and Mr Bright has a similar example 

 of Orgyia antiqua ; Schultz records a Beinas cori/li with female head 

 and antennae and a male thorax and abdomen. Lateral gynandro- 

 morphism of the external characters, excluding the genitalia, is common. 

 But in a very large number of instances the halving is not quite 

 perfect. 



From those insects which show an almost complete halving of 

 external characters we pass gi-adually to those which show a very 

 coarse mosaic arrangement, the male element preponderating on one 

 side and the female on the other, and thence to those where the two 

 elements are almost evenly balanced. 



In others the coarse mosaic is met with, but one or other sex greatly 

 preponderates. In others again the mosaic is found finer. 



A fine mosaic arrangement, where there is a veiy intimate bilateral 

 mixture, gives the " gynandromorphe superpose," such as the Polyom- 

 matus icarus figured later (PL XXIV, fig. 19). 



The upper side of this is predominantly male, but amongst the 

 small patches with blue scales and androconia, less numerous patches of 

 brown scales of female shajje occur. Orange scales representing female 

 lunules also occur on the margins. The underside is predominantly 

 female. Wheeler has described " blended gynandromorphs " with the 

 form of one sex, the colours, sculpture or pilosity of the other. In these 

 I believe the mosaic arrangement still holds good, but that cells of male 

 and female type are arranged much as the cells in a plant chimaera 

 (graft hybrid). 



In these the core, which gives the form, is made purely of cells of 

 the one sjjecies and the external layer or layers of cells made purely of 

 those of the other species. Cells of intermediate character do not occur 

 in these plants, nor do they, I think, occur in such gynandromorphs, 



