59 



Against the use of tlie expression "subiinago" in itself, for the 

 pupal stage of Lepidoptera and other Holometabola, de Meyere does 

 not seem to liave fundamental objections, for as is seen from his 

 own words, he declares that the pupa might be considered as an 

 "inactive subimago," though he himself would prefer the name "in- 

 active larva." 



In this preference I cannot agree with him. The conception 

 "larva" implies the presence of provisional organs, as well as the 

 manifestation of a metamorphosis, the moment of which tixes the 

 tinal point of larval life. Now it is clear, that this point lies at the 

 passage from caterpillar to pupa. Therefore the latter cannot be called 

 an "inactive larva", but ou\y an "inactive subimago". It might 

 even be asserted to represent an "inactive imago", for the provi- 

 sional larval organs have disappeared, the imaginal organs on the 

 contrary being all present, though still unable to functionate. 



But it is especially against the inference, that this subimaginal stage 

 should have been provided with a sufficient mobility to enable it to 

 fly about, after the fashion of the caddisflies when they leave the 

 water, that de Meyere raises objection. According to his view, it 

 is much more probable that in none of their phylogenetic stages the 

 Lepidoptera or any of their kin : Panorpata, Diptera, or Neuroptera, 

 were ever on the wing before the very last moult, so before they 

 fully deserved the designation "imago". 



Now I must admit, that this supposition of the occurrence of a 

 flying subimaginal instar among the ancestors of these groups of 

 Insects is merely a hypothesis, which can only be supported by argu- 

 ments of probability, while most assuredly important objections can 

 be opposed against it. One of these difficulties I will indicate my- 

 self: Holometabolic Insects may indeed be compared still to other 

 Hemimetabola than precise!}' the Agnatha, and moreover to Ame- 

 tabola also, and this comparison may lead to raising the question, 

 if the pupal stage might not best be compared to the last instai- 

 but one of these groups, to which belong insects, whose diflerent 

 instars are much more similar to each other than those of Holome- 

 tabola, because all of them differ less from the imaginal condition, 

 or, what means the same, because they have all deviated in a 

 minor degree from the original Insect-type. 



In them we see the wings protrude at an early stage as lateral 

 outgrowths of the dorsal body-wall and increase in size at each 

 following ecdysis, though entering into function at the last one only. 



Why should this course ot development be less primitive than 

 that of caddisflies? Might not the cui-ious phenomenon, that 



