383 



liaviiii^- disoovored tliciii ag-ain respectivoly in 1875 and 1883. 

 Though convincod that the larva is a phylogen(3tically old torm, 

 PouLTON has still contributod miich to propagate a ncw idoa of 

 the pupal stage. Many argunients are iised by liini to confirni 

 his asscrtion that the pupa is a subimaginal stage, whieh lias 

 beconie inimovable. 



As his chief proofs I mention the well-developed external ge- 

 nital organs, the simpler struoture of the wings, the large antennae 

 and wings of those feniale forms, which in the imaginal state 

 possess short ones, etc. The agreement in colour between Cater- 

 pillar and pupa has been observed by him, but that feature he 

 considered of little value. 



J. F. VAN Bemmelen discovered in 1889, that the definite 

 colour jmttern of the imagines is preceded in the pupal state by 

 a simpler one. More recent investigators confirmed this and Bryk 

 (1914) demonstrated its persistancc in an aberrative imaginal f orm. 



Packard (1889) discovered that Bombus^ before emerging from 

 the pupa, moults once more, so that this reminds us somewhat 

 of the subimaginal stage of the Epliemeridae. 



In all these ways of considering the pupal instar it was taken 

 for granted that all the Holometabola originated monophyletic- 

 ally. To this idea Swammerdam has certainly contributed a great 

 deal, and Lubbock too was of the same opinion. 



Brauer (1884, p. 318) directed attention to this problem 

 without solving it, however. As it is closely connected with an- 

 other question, naraely : is it necessary that the setal pattern of 

 the caterpillars agrees with that of the other larvae or can it be 

 derivcd from it, I thought I had better give a short synopsis of 

 the literature on this problem. 



MiALL (1895) considers the incomplete metamorphosis of the 

 Orthoptera to be a primitive one. 



BoAS (1899) thinks the meaning of the pupal stage is to pro- 

 cure the animal the opportunity of developing its wings. His 

 decisive assertion (p. 397) is incomprehensible to me: "Es ist 

 demnach ausgeschlossen, dass das Insekt vor der letzten Hau- 



