THE CANADIAN ENTOMOLOGIST 367 



at the end of their paper, and worse still is the practice of having 

 the explanations scattered throughout the text. In many in- 

 stances there is no real reason why the explanation and the figure 



10530 sorcir.3 fOUlO ID at.; Ji.-£t,I 



Fig. 30. 



should not appear on the same page. An author fails to realize 

 that all readers do not share his burning interest in the question 

 treated, and unless he can command their attention, sometimes 

 in spite of themselves, he is likely to lose their interest. 



Figure 31 is a bar method of comparing percentages. An 

 illustration of this sort is easily read, and the reader can grasp 

 readily the fact that 48 per cent, of the species of insects in New 

 Jersey feed on vegetation and that 16 per cent, are predatory, and 

 so on. The words "on vertebrates" should have been replaced 

 by "injurious to vertebrates," as the* former phrase is somewhat 

 misleading. The shading of the large sections of the bar might 

 also have been made more dense, to bring them out better. A chart 

 of this kind is much more effective than a mere printed statement 

 of the facts. Many readers do not grasp printed figures easily, 

 and if you desire to reach this class you must visualize the facts 

 for them. 



Figure 32 needs practically no explanation. It is simply a 

 graphic method of placing figures or amounts before a reader and 



