PERFECT INSECT. 23 



that oi pupcE when the wing-cases and forming wings 

 show more or less, and that of perfect insects or 

 imagos when (with all kinds that have powers of flight) 

 they have their wings complete.* 



When the insect has come out from the chrj^salis or 

 pupa, it is perfect ; it will grow no more, excepting 

 from its wings expanding in some kinds (as with Moths 

 and Butterflies) in which they were not fully spread, 

 or were folded tightly in the chrysalis case. The 

 internal organs are now also perfect, and its remaining 

 work is to propagate its species. 



Many kinds, which have heen ruining our crops for 

 months as voracious grubs, are now harmless during 

 the short remainder of their lives ; but some, on the 

 contrary, of our worst crop-pests, such as the Turnip 

 and Mustard Beetle, live through the" winter, and 

 in their perfect state ravage as badly as or worse than 

 they did in their first stages. These points, or points 

 such as these, regarding the condition of insects_ at 

 different times in the year, and their general habits, 

 are what we need to know about much more than their 

 structure, and this knowledge is to be gained in part 

 by careful personal observation, in part by study of 

 sound recorded information. Therefore, before going 

 on to field observations, it will be serviceable, firstly, to 

 take notice of some points of structure which all per- 

 fect insects possess in common ; and afterwards to see 

 how, by some few and very clear difi"erences (when 

 noticed together with the different transformations of 

 which we have just been speaking), we may tell what 

 order an insect belongs to, and thus advance to a 

 general idea of its method of life. I trust to be able 

 to show that by mastering a few simple details we may 

 gain all the knowledge we want, as a foundation, 

 either for field use or to carry on further study of 

 insect life scientifically, if we wish. 



* Some of the special exceptions are mentioned under the details of 

 the different orders. 



