INTRODUCTION. 



periods of growth and development. As soon as bursting from the 

 pupal ease takes place, the creature is then literally the perfect insect, 

 inasmuch as there is no further change or development. It is well to 

 bear this in mind, as it is a popular notion amongst 

 certain people not conversant with natural history 

 that small moths and flies are simply "young ones." 

 Such, however, is not the case, for while there is 

 often a difference in size amongst individuals, of 

 the same species, it should be remembered that 

 no growth takes place after full pupal emergence. 

 In demonstration of this, perhaps a typical case 

 may be taken viz., that of the Small Tortoiseshell 

 Butterfly, Vanessa urticce. Fig. 5 represents the 

 pupal case. In fig. 6 we have a representation of 

 the first emergence from the pupal case ; in fig. 7, which is later, 



Fisr. 5. Pupal case of 

 Small Tortoiseshell 

 Butterfly (Vanessa 

 urtica'). (Flatters.) 



Fig. o. First emergence of Tortoiseshell Butterfly from pupal case. (Flatters.) 



the wings are slightly more expanded ; and in figs. 8 and 9 we see 

 a representation of the fully developed butterfly. The whole process 



Fig. 7. Emergence of Tortoiseshell Butterfly more fully advanced. (Flatters.) 



of development, which is chiefly a question of wing expansion, takes 

 at most only a few hours. 





