123 



having diwovcrod them again respectively in 1875 and 1883. 

 Though convinced that the larva is u phylogenetieally old form, 

 PouLTON has still contributed much to propagate a now idea of 

 the pupal stage. Many argumonta are used by him to confirm 

 his assertion that the pupi is a subimaginal stage, which has 

 become immovable. 



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

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

 and wings of those female 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. VAX Bemmelen discovered in 1889, that the definite 

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

 a simpler one. More recent investigators confirme<l this and Bryk 

 (1914) demonstrated its persistancc in anaberrative imaginal form. 



Packard (1889) discovered that Boinbun, before emerging from 

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

 of the subimaginal stage of the Ephemeridae. 



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, namely : is it necessary that the setal pattern of 

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

 derived 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- 



