816 INSECTA. 



but an inanimate half-formed mass, is now transformed into an animal 

 decked with the most vivid colors, and rejoicing in its new existence. The 

 operation of expanding their wings in by far the greater number of insects 

 occupies only a few minutes; in some butterflies, half an hour or an hour; 

 and some species of sphynx require several hours or even a day for this ope- 

 ration. In certain tipulce and the ephemera, however, this process is almost 

 instantaneous ; and in some species of this last genus, the insects, after be- 

 ing released from the puparium, and making use of their expanded wings 

 for flight, undergo a slight and further metamorphosis. They fix themselves 

 by their claws in a vertical position upon some object ; withdraw every part 

 of the body, even the legs and wings, from a thin pellicle which covered 

 them like a glove ; and so perfect is the resemblance of this exuviae to the 

 insect, as to be at first sight mistaken for it. 



When the developement of the perfect insect is thus fully completed, it 

 immediately begins to exercise its new powers in their destined functions. 

 It walks, runs, or flies, in search of food, or of the other sex of its own spe- 

 cies if it be a male, that the great purpose of its existence in this state may 

 be fulfilled, the continuation of the species; and so unerring are its intuitive 

 perceptions of the food which is proper, and the protection which it requires, 

 that the new-formed being becomes at once a free denizen of the air, distin- 

 guishing with more than botanical skill the plants and their juices which 

 are necessary for its wants; and guided at once to results which in other be- 

 ings are only acquired by the slow lessons of experience or education. The 

 duration of insect life in \heiviago or perfect animal is subject to some vari- 

 ations, but in general concludes when reproduction is perfected. There is 

 not, as in the larger animals, a duration of a medium period, only liable to 

 be shortened by accident or disease ; but a conditional one, dependent on 

 the earlier or later fulfilment of a particular function. The general law 

 regarding this period among insects seems to be, that a few days, or at most 

 a few weeks, after the union of the sexes, and the deposition of the ova by 

 the female, both individuals perish. The period of eflfecting this is longer or 

 shorter according to the species. Some, as several ephemera:, live only a few- 

 hours, and never enjoy the enlivening light of the sun, appearing only to 

 fulfil the great purpose of nature after sunset, and having finished this in the 

 course of a few hours, by dropping their ova on the surface of their native 

 waters, perish before the dawning of another day. Others, as flies, moths, 

 butterflies, and indeed the greater part of insects, take a few days or weeks, 

 to accomplish the same purpose. A comparatively small number, such as 

 some of the larger coleoptera, orthoptera, &c., exist from six to nine, twelve, 

 and even fifteen months ; and some instances have been recorded of particu- 

 lar species, when kept and fed, having their existence prolonged considerably 

 beyond this term. But these are exceptions to the general rule. And it is 

 to be remarked further, that insect life seems to follow a different law from 

 that which prevails among vertebrated animals, where the duration of 



