46 



edge of the former, then s. poststigmcdis becomes prostigmal in 

 respect to this stigma. 



In that case there must exist two s. jiTostig males. If s. infra- 

 stigmalis also takes part in this shifting, there are three s. pro- 

 stigmales. This then would agree with Fracker's bisetose and 

 trisetose K.-group. 



On the mesothorax and the metathorax s. poststigmalis can be 

 removed so much, that it comes in one vertical line with s. su- 

 prastigmalis. 



It is easy to imagine, that hereby s. prostigmalis is pushed 

 upwards and thus occupies the place of s. suprastigmalis. This 

 one is also shifted and appears between its old place and s. dorsalis, 

 i. e. on the place of s. dor solater alls. 



It is also possible that s. infrastigmalis is removed downwards 

 and so appears on the place of s. basalts. I think that this expla- 

 nation is very artificial, but still it seems to me better than that 

 given by Fracker. That a stigma can be shifted in such a manner 

 that it plunges under the setae, without exerting any influence 

 on their position, seems to me highly improbable. I think however 

 that the cases mentioned sub 1 , 2 and 3 form an argument against 

 this explanation, which is given here for the sake of com- 

 pleteness only. 



Besides it seems to me entirely incorrect to introduce in a 

 nomenclature hypothetic views on homology. In human anatomy 

 we might as well call the muscles and bones of the arm and 

 legs by the same names, if they were considered homologous for 

 some more or less probable reason. In my opinion a nomenclature 

 ought to be a means for a short and clear description and it 

 should not be the expression of hypotheses on which various 

 investigators have different opinions. Through this, it is made 

 difficult for outsiders to understand the terminology, and the in- 

 vestigators of the setal pattern themselves will, each with the 

 same right, claim their own hypothesis to be the right one. 



