GENERATION OF INSECTS. 423 



or without their development being attended with any loss of activity 

 or diminution of voracity, as, e. g. in the Ilemiptera and Orthoptera. 



The successive states of an apodal worm, of a worm with feet, and 

 of one with feet and wings, being accompanied likewise Avith the ac- 

 quisition and perfection of the antennal and visual organs of sense, 

 and of the internal and external organs of generation, and often with 

 great changes in the digestive, muscular, and nervous systems, in the 

 development of one and the same insect, have been emphatically 

 termed the " metamorphoses." And entomologists availing them- 

 selves of the neat definitions of the pupaj by Linnaeus, have defined 

 various kinds of metamorphoses under special heads, as the " coarc- 

 tate," " obtected," " incomplete," " semi-complete," and " complete " 

 metamorphoses. 



The progress of the insect through these several stages being in 

 many species interrupted, and active life enjoyed for a longer or 

 shorter period under one or other of the immature forms, these have 

 been sooner and more prominently brought nnder the notice of the 

 naturalist, than if they had been to be sought for, as in the bird or 

 mammal, in the early periods of the development of the minute 

 embryo. They have consequently had assigned to them a character 

 of singularity and exception which they do not intrinsically 

 deserve. The diiferent stages of development have been likewise, 

 for the most part, studied only in the instances in which they are 

 manifested by insects after exclusion from the G.%g, and thus their 

 minor modifications and differences have attracted more attention 

 than their essential resemblances and relations to one and the same 

 type and course of development. As soon as the young insect 

 breaks through the egg-shell it is, in modern Entomology, a larva, 

 whatever grade of development it may have attained in ovo : during 

 the period when it acquires the wings, and until their complete 

 acquisition, it is a pupa. 



From the importance which has been assigned, in some estimable 

 entomological treatises and classifications, to the developmental 

 changes of insects, and the special denominations that have been 

 multiplied to express them, you might suppose the " complete," the 

 "semi-complete," the "incomplete," the "obtected," and "coarctate" 

 metamorphoses, to be different degrees, if not distinct kinds of trans- 

 formations. But the insects which are said to be subject to the 

 semi-complete and incomplete metamorphosis pass through the same 

 kind and amount of change as those characterised by the obtected or 

 coarctate pupa. The differences resolve themselves essentially into 

 the place where, and the time in which, they assume and quit tlie 

 vermiform state. 



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