300 



very primitive qualities in the pattern of the wings of the Hepia- 

 lidae, but nevertheless could show at the same time great secon- 

 dary alterations in it. 



It does not seem advisable to me to look upon the pattern of 

 one segment of one single representative, as the generalized type 

 of the Jugatae, from whieh the generalized type of the Frenatae 

 has descended. And this applies in a high degree to the prothorax. 



In a preceding chapter I think, I have proved sufficiently that 

 the thorax on the whole is not bnilt primitively, that the stigmata 

 on its surface have been shifted and that the wing-nuliments 

 very soon bring about changes in these segments. 



By nearly all the writers the prothoracic stigma is considered 

 to have been shifted towards the oral side and it is strange to 

 choose this very segment as a starting-point. 



It seems to me a very unfoHunate accident that the setae on 

 the prothorax of Hepkdus lupulinus (1. c. p. 1 7) are also about 

 fifteen and that they were in approximately (!) the same position 

 as on the hypothetical segment. 



Another objection I have to Fracker's assertion is, that x and 9- 

 on the prothorax should be homologous with x and b of the 

 abdomen (c.f. on this point my PI. X, fig. 15). 



On the prothorax we find these setae in front of the stigma, 

 on the abdomen behind it, without there being any change in the 

 position in regard to the other setae. There we gei the impres- 

 sion as if the stigma had passed under these setae, a kind of 

 dislocation, the possibility of which I cannot understand. I ani 

 convinced that a seta which is situated in front of the stigma must 

 remain prostigmal, and that it will either disappear in case the 

 stigma is shifted, or that it will display the traces of the shifting 

 of the stigma in its situation on the segment. ïherefore I think 

 that the seta called UI B by Quail may agree with a prostigmal 

 seta, even if this seta is sometimes placed a little higher. 



The "proofs" mentioned by Fracker of the shifting of £ and 

 p do not appear to me to be convincing. The upshot of these 

 arguments is always the preconceived idea, that we must consider 



