4 LEPIDOrTERA. 



winged groups — especially some of tlie Tineina — the nervure3 

 are fewer in number and nearly parallel. The neuration of 

 the hiud wings is similar to that of the fore wings, with 

 alterations of position to suit their function, which appears 

 to be that of a floating or buoyant support, while that of the 

 stronger fore wings is progressive. In the vast majority of 

 species the fore wings slightly overlap the hind, and in the 

 case of those which fold the hind wings together, the latter 

 usually possess near their base a short stiff bristle, or two 

 bristles, which, fitting into a groove in the fore wings, keep 

 both together and in position. This bristle is present in 

 nearly all moths, and absent in all our butterflies. 



The colouring and marking of the wings are due entirely 

 to the scales with which they, as well as the body and legs, 

 are covered, and which are so well known as the dust which 

 adheres to the fingers when a moth or butterfly is handled. 

 The colours and markings are arranged in definite patterns, 

 and it is by these and the shapes of the wings that species 

 in this group are mainly recognisable. In many species, 

 however, these colours and markings are subject to con- 

 siderable modification, and the extent to which a pattern may 

 in both respects vary without losing its specific character is 

 a most curious and interesting subject of study. 



The legs, six in number, consist, as in the higher animals, 

 of three main portions — the femur (thigh), tibia (shank), 

 and tarsus (foot), and the latter is divided, not into toes, 

 though it has a pair of claws at the extremity, but into 

 five movable joints. In many cases the upper and undivided 

 portions of the leg are furnished with spines or spurs. 



All Lepidopterous insects pass through a series of changes, 

 which is known as a "complete " metamorphosis. At certain 

 periods of its existence each creature suffers a total alteration 

 in appearance, once into a helpless and comparatively shape- 

 less state without external organs, and from this directly into 

 the state in which all the organs are perfect. 



This complete metamorphosis is accomplished, as is also 



