232 INSECTA. 



part of the body are soft and membranous. The caterpillars, or 

 larveEj* live for some time in this condition, and frequently change 

 their skin as they increase in size, until at length, the last skin of 

 the larva being thrown off, the animal presents itself in quite 

 a different form, enveloped in an oblong case, without any ex- 

 ternal limbs, and almost incapable of the slightest motion, re- 

 sembling rather a dead substance than a living creature ; it is then 

 called a chrysalis, nymph, or pupa^ (Jig. 105, B). 



On examining attentively the external surface of this pupa, we 

 may discern, in relief, indications of the parts of the butterfly con- 

 cealed beneath it, but in a rudimentary condition. After some time 

 the skin of the pupa bursts, and the imago, or perfect insect, issues 

 forth, moist and soft, with its wings wet and crumpled ; but in a 

 few minutes the body dries, the wings expand and become stiff, 

 and, from being a crawler upon the ground, the creature is con- 

 verted into a gay and active denizen of the air (Jig. 105, c). 



Such is the progress of the metamorphosis when complete ; but 

 all insects do not exhibit the same phenomena. Those genera 

 which, in their mature condition, have no wings, escape from the 

 egg nearly under the same form as they will keep through life ; these 

 form the Insecta Ametabola^ of authors : and even among those 

 tribes which, when perfect, possess instruments of flight, the larva 

 frequently differs from the complete insect only from its wanting 

 wings, and the pupa is recognisable by being possessed of these organs 

 in an undeveloped or rudimentary state ; an example of this is 

 seen in the house-cricket, (Jig. 102,) in which A represents the 

 imago ; B, the pupa ; c, the full-grown larva ; D, the young just 

 hatched ; and E, the eggs. 



(271.) The extensive class of INSECTS has been variously arranged 

 by different entomologists, and distributed into numerous orders. 

 Among the different systems which have been given, we select the 

 following as best calculated to render the reader acquainted with 



* So called by Linnaeus, because in this condition the perfect form of the insect is 

 concealed as it were under a mask. Larva, Lat. a mask. 



t The two first of these names are purely fanciful ; the last is derived from pupa, 

 a baby wrapped up in swaddling bands. 



J , without ; ptruZoXvi) change. 



$ The classification of insects here given is that of Burmeister, which we select 

 without giving any opinion as to its relative merits compared with others adopted by 

 different entomologists, but simply as being most convenient for our present purpose. 

 Manual of Entomology, translated from the German of Dr. Hermann Burmeister by 

 W. E. Shuckard, 8vo. 1836. 



