42 ELEMENTS OF ENTOMOLOGY. 



The opening through which they pass is always at the same part of the 

 skin, a httle above tlic trunk, between the wings and a small piece 

 which covers the head : different fissures are generally made in the 

 same direction. When the operation begins, there seems to be a vio- 

 lent agitation in the humours contained in the little animal ; the Huids 

 being driven with rapidity through all the vessels, the limbs and various 

 parts of the body are put in motion, and by rcpeatetl elforts it breaks 

 through the brittle skin that envelopes it. Those inclosed in cones or 

 cases, after bursting through the pupa covering, have another difficulty 

 to overcome, that of piercing througli the inclosure, which in many 

 instances is of a stronger texture than the case of the pupa. For the 

 accomplishment of this, most insects are provided with a li(pior, which 

 they discharge from the moulli upon that part of tlie cone through 

 which they intend to escape; and this so moistens and weakens it, that 

 after a short time they force their passage through with some facility. 

 Some insects not provided witii this Huid leave one end of their cone 

 weaker than the rest, and close it only with a few threads, so that a 

 slight eftbrt of the head enables the insect to burst from its prison. 



The butterfly or moth on emerging from tlic jnipa is moist, the ab- 

 domen swollen, the antenuie bent down, and the wings crumpled, 

 small, and shapeless. These parts are gradually unfolded, and assumq 

 their destined form. The wings, which at one instant are small and 

 like four little l)uds at the sides of the thorax, in a few minulcs after 

 acquire their full size ; and the fibres, which were at first flexible, be- 

 come hard and rigid like bone. In proportion as the fibres lose their 

 flexibility, the fluids which circulate within them extend, and the wings 

 cease to act; so that, if any extraneous circumstance arrests the progress 

 of this fluid through the fibres at the first instant of the moth's escape, 

 the wings immediately become crij)pled, and never afterwards assume 

 any other form. Most insects, soon after they have attained their per- 

 fect state, void an excrementitious sid)stance, which in some places, 

 where the insects were abmidant, has produced reports of showers of 

 blood. 



Of the IMAGO or Fcrfcct Slate. As the present work is not in- 

 tended to enter into all the particulars relative to the lidhildtions, Jhuc/, 

 modes of fife, SjC. I must refer the student to IMcssrs. Kirhj/ and Spences 

 popular Inf 1-0(1 luium, in which much information on these points will 

 be found collected together. 



