DRAGON-FLIES, ETC. 213 



of that part of the river, made them appear as 

 though covered Avith rich purple blossoms, which 

 produced a most enchanting effect. 



The individual represented in Plate VI. is a male, 

 in its most mature state, after the wings have 

 assumed their richest purple, the other sex being 

 much more sober in its style of dress. The female 

 of Calopteryx has indeed the body as brightly 

 tinted as that of the male, with the difference that 

 it is green instead of blue ; but the wings are nearly 

 transparent, being only just tinted with a suffusion 

 of soft silky brown ; and another distinction is that 

 the neuration or net-work of the wings is decidedly 

 more open in its character. Tbe sexual differences 

 of aspect of the graceful Calopteryx Virgo, as also 

 analogous differences in many other insects, often 

 led our early classifiers to make separate species of 

 the two sexes; and in this way uselessly mul- 

 tiplying names and lists, and making endless con- 

 fusion, which had to be set to rights by the slow 

 means of gradual discoveries, of a kind which, as 

 offering small reward, are only worked out by the 

 labours of a few devoted enthusiasts. 



There are also other circumstances connected 

 with the beautiful Calopteryx Virgo Avhich have led 

 to the erroneous multiplication of species ; first, the 



