196 THE EPHEMERINA. 



darken the air^ and often to cover the shore^ the 

 ships^ and other objects with their dead bodies to the 

 depth of an inch or more. Another species, the 

 Ephemera albipennis, inhabits the Seine at and near 

 Paris, where it suddenly makes its appearance for a 

 few days in July or August in such numbers, that 

 Latreille describes its white wings as producing the 

 appearance of a heavy fall of large flaked snow. 

 These curious circumstances have long been known, 

 having been described in the former case by Swam- 

 merdam, in the latter by Reaumur; but within the 

 last few years M. Imhoff has described a third species, 

 which occurs in the same profusion in and about the 

 town of Basle in Switzerland at the end of August or 

 the beginning of September, and is found in the 

 morning lying dead in heaps in front of the houses 

 situated close to the river. 



The females drop their eggs in small masses into 

 the water as they rise and fall above its surface, 

 and while thus engaged many of them are probably 

 snapped up by the expectant fishes, which voraciously 

 devour their bodies when they fall dying into the 

 water ; in fact, from the abundant supply of food thus 

 furnished to the fishes, we are told by Geofiroy that the 

 fishermen in some localities of France denominate 

 them " Manne des Poissons/' or the Fishes^ Manna. 

 Our own anglers are rather less poetical in their 

 ideas, although they have contrived to find some 

 resemblance between the turned-up tail of the May- 

 flies and the same appendage in the Drake, whence, 

 they say, are derived the names of Grey and Green 

 Drakes, often applied to these insects. 



