ANlNULOSA: INSECTA, 



2SS 



wings. It is active and locomotive, and is generally very like 

 the adult in external appearance. The " pupa," again, is a 

 little larger than the larva, but really differs from it in nothing 

 else than in the fact that the rudiments of wings have now 

 appeared, in the form of lobes enclosed in cases. The " pupa " 

 is still active" and locomot-ivei and the term "nymph" is usually 

 applied to it. The pupa is converted into the perfect insect, 

 or " imago," by the liberation of the wings, no other change 

 being requisite for this purpose. From the comparatively small 

 amount of diflference between these three stages, and from the 

 active condition of the pupa, this kind of metamorphosis is 

 said to be "incomplete." 



In some members of this section however — such as the 

 Dragon -flies-^ the larva and pupa are aquatic, whereas the 

 imago leads an aerial life. In these cases there is necessarily 

 a considerable difference between the larva and the adult ; but 

 the larva and pupa are closely alike, and the latter is active. 



Section 3. Jiolometabolic Insects. — These — comprising the 

 Butterflies, Moths, Beetles, &c. — pass through three stages 

 which differ greatly from one 

 another in appearance, the 

 metamorphosis, therefore, be- 

 ing said to be "complete." 

 In these insects (fig. 86) the 

 " larva " is vermiform, seg- 

 mented, and usually provided 

 with locomotive feet, which 

 do not correspond with those 

 of the adult, though these 

 latter are usually present as 

 well (fig. 86). In some cases 

 the larva is destitute of legs, 

 or is " apodal." The larva is 

 also provided with mastica- 

 tory organs, and usually eats 

 voraciously. , In this stage of 

 the metamorphosis the larvae 

 constitute what are usually 

 called " caterpillars " and 

 "grubs." Having remained 

 in this condition for a longer 

 or shorter length of time, and 

 having undergone repeated changes of skin, or "moults," ne- 

 cessitated by its rapid growth, the larva passes into the second 

 stage, and becomes a " pupa." The insect is now perfectly 



-Metamorphosis of the Magpie- 

 moth [Phalana grossulariata). 



