STRUCTURE OF FUP^. 291 



structure of pupae, rather than stop to refute cir- 

 cumstantially the preceding theory of Harvey and 

 Goedart. 

 i In the pupa state, then, we may remark, that the 

 I legs, wings, and other external appendages of the 

 insect, are, in the greater number of instances, closely 

 folded up and enveloped by an external covering, 

 usually of a membranous structure, and differing con- 

 siderably both from the skin of the larva and from 

 that of the perfect insect. It is as different, indeed, 

 as the winter envelope of the bud of a tree is from 

 ' the bark or from the cuticle of a leaf. The angular 

 forms exhibited in some chrysalides are for the pur- 

 pose of encasing particular limbs, &c., of the insect 

 which Providence has not seen meet to fold down 

 smoothly to the body. The spines, hooks, and hairs, 

 again, which are also of occasional occurrence, and 

 which Goedart strangely enough mistook for feet,* 

 are manifestly for aiding the animal in casting its old 

 skin, as has been explained in a preceding page ; 

 while the grooves, ridges, and other markings, are 

 the indications of the various members of the insects 

 ] folded up, or otherwise disposed under them. 

 j As we have shown all the parts of the perfect in- 

 sect contained in the caterpillar, so these can be much 

 more easily exhibited in the pupa, particularly when 

 near its final change ; for in more early periods the 

 substance is so soft and pulpy — almost fluid indeed 

 i — that it would be next to impossible to develop 

 ! them artificially. In some pupae the parts can even 

 ; be seen through the membranous envelope, which in 

 other cases requires, for this purpose, to be removed. 

 In order to exhibit this, we shall select a few instances 

 in which the facts may be readily verified, by those 

 who will take the trouble of breeding the insects. 

 I The first we shall advert to is that of the chame- 

 * Goedart, de Insectis, 77. 



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