THE El']IE3Ii:it.\, OK MAY-FLY. 43 



insect ; and from the same feather, slightly stained Avith 

 purple, for the grey-drake, or perfect form of the female. 

 The term May-fly is very indefinite, standing for all sorts of 

 different insects in different counties. 



In this country, the May-flies appear about the end of May 

 and the beginning of June, and continue for about three weeks. 

 The green-drake issues from his nymphal state abnost at any 

 hour in the day, but especially when the sun is shining. lu 

 Sweden, the birth of these insects is confined nearly to the 

 evening, about sunset ; but it is quite an error to assert that 

 our British Ephemera vulgata emerges from the water only 

 in the evening. Some species of Ephemeridae appear in the 

 most astonishing swarms, in some parts of Europe. Scopoli 

 tells us, that so great an abundance of E. vulgata sometimes 

 occurs near the Lake Laz, in the month of June, that the 

 inhabitants of the district are quite disappointed if they do 

 not collect twenty cartloads of insects for manure ! " Between 

 the 10th and 15th of August is the time when those of the 

 Seine and the Marne, which Reaumur described, are expected 

 by the fishermen, who call them marina ; and when their 

 season is come, they say, ' The manna begins to appear ; the 

 manna fell abundantly such a night.* " These immense swarms 

 of Ephemeriche have been noticed in Holland, Switzerland, and 

 France, and have been compared to falling flakes of snow. 

 " The myriads of Ephemerae which filled the air," says 

 Reaumur, " over the current of the river, and over the bank 

 on which I stood, are neither to be expressed nor conceived. 

 When the snow falls with the largest flakes, and with the 

 least interval between them, the air is not so full of them as 

 that which surrounded the Ephemerae." The occurrence of 

 such countless swarms of Ephemeridcc is unknown in the 

 British Isles. 



