202 HIDDEN BEAUTIES OF NATURE 



The eyes of insects are very small, and to be seen 

 properly must be viewed under the microscope ; yet 

 we are told by Dr. Carpenter, in the ' two eyes of the 

 common fly there are as many as 4,000 ocelli or 

 facets ; in the eyes of the cabbage-butterfly there are 

 about 17,000; in the dragon-fly 24,000; and in the 

 mordella beetle 25,000 ! ' Such figures as these, 

 descriptive of mere points, if well considered, appal 

 us much in the same manner as do the calculations 

 connected with astronomy. 



Leuwenhoek, more than 200 years ago, arranged 

 the eye of an insect so that he was able to see through 

 the facets, and could see buildings many yards 

 distant so distinctly that he could tell which windows 

 were open and which shut. This famous microsco- 

 pist, although using very inferior magnifying powers, 

 was well acquainted with a great deal of what is 

 now known and revealed by greatly improved 

 appliances. 



