THE LEPIDOPTERA. l6l 



morphoscs appear to eclipse everything else which may have to 

 do with the progressive and systematic development. The em- 

 bryonic life, or that within the egg, the moults, and the first and 

 second metamorphoses, are then the more or less important and 

 marked stages in the evolution of the lepidopterous insects. Some 

 caterpillars do not assume, cither at first or at all, a perfect larval con- 

 dition, and then the embryonic stage has been less complete than 

 usual. Thus the caterpillars of the CocJdiopodidcd are legless ; and 

 this state of things is not restricted to that genus. In other in- 

 stances the larvae, when hatched, present evidences of advanced 

 development, and in one genus the pupa appears to be far 

 advanced towards the future condition. The extraordinary variety 

 of the shape and colour of the caterpillars of the Noctuina, 

 and the identity of the moths have been noticed ; but the study 

 of the phenomena repays, for it adds to our conception of the 

 mysteries of the metamorphosis. 



It is interesting to note the structural relations between those 

 Lepidoptcra which have a scanty supply of wing scales and the 

 Hynicnoptera, and to observe the curious mimicry of shape and 

 tints which then prevails. 



The metamorphoses of the Lepidoptera may be classified, for 

 the sake of convenience, as follows : complete, incomplete, and 

 retrograde. The duration of the stages, however, difters, and 

 necessitates a second scheme. The metamorphosis takes place 

 once in the year, and the eggs remain unhatched until the spring 

 — a long embryonic stage — the other stages being short. The 

 metamorphosis takes place twice or more in the year, and the 

 eggs of the last brood remain through the winter and into spring. 

 Here the embryonic stage differs in length. The metamorphosis 

 may not be completed in the summer and autumn, and the chry- 

 salis lives as such through the winter and into the early summer. 

 The caterpillar may hybcrnate, and the metamorphosis may take 

 place early in the year ; or the caterpillar stage may last more 

 than a year. It is perfectly evident that closely allied Lepidop- 

 tera have different forms of metamorphosis, and that the pheno- 

 menon has been acquired in accordance with a law. 



