EPHEMERAL AND DUN PLIES. 65 



blue-dun, which may be considered as the type, 

 through all the gradations of iron-blue, violet-blue, 

 ashy grey, and pale blue. The yellow ephemera 

 or duns are still more difficult to define, as there 

 are few even of the former that do not exhibit a 

 yellowish intermixing tinge about some parts of 

 their little frames. Often it appears in exquisite 

 orange bars over the abdomen ; but they derive 

 their character from the yellow being more 

 strictly predominant. In some may be perceived 

 a slight mixture of bright yellow with a larger of 

 ashy dun. When both colours are bright, an 

 elegant tint of green is produced. In others 

 again, as the little yellow May-fly, bright yellow 

 prevails without mixture. Of all these the series 

 are wonderfully varied, some having orange bodies 

 and dun wings, while in others the orange is shed 

 over the wings, and the dun body serves as a foil 

 to them. 



"The successional change of colour which 

 tabes place in the series of ephemera, as they ad- 

 vance from the spring to summer, and as they 

 retrograde again towards autumn, has not escaped 

 the notice of anglers ; and we find in most of the 

 directions for fly-dressing the subject practically 

 glanced at ; but no systematic arrangement of the 

 series has been attempted. All that has been 

 hitherto noted is, that in the early spring months 

 the predominating colour of the winged insects 

 F 



