6] 



only appears a long time after the stage in which the rudiments of 

 the wings first become visible. 



Now wliat is true for the colour-pattern, may as well be applied 

 to the wings themselves. 



I do not intend to enter into these considerations more profoundly, as it 

 is irrelevant for the solution of the question, whether or no the colour- 

 pattern on the wing-sheaths of Rhopaloceran pupae possesses phylo- 

 genetic significance. On the contrary it seems to me that in this 

 way the question is made unnecessarily iuli-icate. For the diffe- 

 rence between the Lepidopterous pupa and the imago emerging from 

 it, as well as between this |)upa and the last iiistar but one in lle- 

 mimetabola, only consists in the limited mobility and the temporary 

 suspension of food-supply and excretion in the |)upa. In my 0|)i- 

 nion there can be no doubt that it has lost these functions, and that 

 this loss happened gradually. For we are justified in considering 

 the sculptured and movable pupae of primitive Lepidoptera as more 

 original forms than the mummie-pupae, which are hardly mobile. 

 Why then should not absence of colour and of markings be the con- 

 sequence of a gradual regression of these characteristics? 



Of course this explanation may be as well applied to Neuroptera 

 as to Lepidoptera ; de Mkyeke himself concedes that the pupae of 

 Neuro|)tera 'mostly live hidden in the earth or in cocoons, and 

 that their chitinous envelope is thin and on/y jworh/ colon/red". (The 

 italics are mine). 



The causes for the regression of existing colour- patterns — viz. 

 darkness and absence of shai-psighted enemies — which obtain all 

 over the animal kingdom — may therefore have exerted their 

 influence on Neuroptera. But this need not involve that the primitive 

 Neuropterous ancestors of recent Lepidoptera already had concealed 

 and immovable pupae. In any case those ancestors had to pass 

 through a long range of thorough transformations, during which 

 especially the youngest larval instars deviated ever more from the 

 original type of the Insect, and in so doing came to differ from the 

 last instar as well as from the last but one. 



Those two stages on the contrary remained alike in all important 

 points, though they came to differ from each other in minor accessory 

 characters, which for the pupae chiefly consisted in the loss of 

 mobility, with all its consequences. But apart from this immobilisation 

 it retained the old primordial characters without or with only small 

 modifications, and where a change still occurred, this depended more 

 on katabolic phenomena, e.g. partial or total extinction of colour- 

 markings, than on progressive alterations. 



