200 METHODS OF STUDY. 



differences between one or other of each set; but it is 

 of great importance to be able to tell whether it is a 

 Wireworm, or Daddy Longlegs grub (or so on), of 

 some sort or other, that is injuring a crop, in order 

 that the right means ma}^ be used to save it from the 

 insect ; and I trust that in the preceding Chapters 

 sufficient information will be found to enable the 

 observer to tell what orders such crop insects as are 

 commonly met with belong to, — that is, whether they 

 are Flies, Beetles or so on ; but either for teacher or 

 student it is serviceable occasionally just to take each 

 Chapter separately, and look at the figures. Thus the 

 student will see, and be able to fix firmly in the minds 

 of those who apply for information, what are the 

 main points of an insect in each stage. 



Say it is the order of Butterflies and Moths that 

 may be under examination ; the student cannot fail to 

 notice that the caterpillars have commonly three pairs 

 of claw-feet, and one to four pairs of sucker-feet, under 

 the body, besides the caudal pair ; also that there are 

 two slightly different forms of chrysalis, belonging 

 respectively to Butterflies and Moths ; and also that 

 the shape of the horns of the Butterfly differs from 

 the many shapes of those of the Moths. If the 

 teacher had tried to explain this without a picture, 

 the pupil would probably have been without an idea 

 of what was described; but one glance at the succes- 

 sive pictures will have told him at once what are the 

 main points of a Butterfly or Moth, and its caterpillar 

 £iud chrysalis. 



The object of minute scientific descriptions is, that 

 we may have a correct knowledge of the appearance of 

 Avhat is described ; but there are few who can tell 

 nearly as well from a description as from a figure 

 what the described thing is like, and often a wrong 

 idea is thus established. I would, therefore, suggest 

 that in first instructions to pupils, teaching should be 

 given as much as possible by the real specimens, if 

 these are available; otherwise by means of good 



