158 EPHEMERAE. 



The numbers in which these creatures escape from 

 the water, are truly astonishing. Under favourable 

 circumstances, they literally fill the air in a few minutes, 

 and their cast skins are like a scum upon the water. 

 Those which appear in the heat of summer are sup- 

 posed to be the longest lived ; for in spring and autumn, 

 when the nights are cold, there is usually a new and a 

 different race every day ; and sometimes two or more 

 between sunrise and sunset. The females of most of 

 the species light upon the surface of the water, and 

 deposit the whole of their eggs ; but there are others, 

 such as that called the grey drake, that gambol over 

 the surface, and only occasionally touch the water. 

 Skilful anglers often take advantage of this, by having 

 an imitation of the green May-fly which they allow to 

 float, and a grey drake farther up the line, which by a 

 nice management of the rod they contrive to make 

 touch the surface only occasionally. Those which sit 

 upon the water, deposit their eggs all at once, in two 

 packets or bags, each containing from three to four 

 hundred. So immediate a change of bulk might derange 

 the action of the little animal, but it is prepared with 

 two air-cells of considerable magnitude, which it in- 

 stantly inflates, and thus is enabled to rise if it shall 

 escape the watchful eyes of the fish ; and as there are 

 thousands for every fish, abundant store of eggs is at 

 all times deposited. We are apt to wonder at this 

 apparent waste of labour upon creatures so small, so 

 short-lived, and so destined for destruction ; but nature 

 knows no labour ; the laws of her productions are 

 simple, certain, and unerring, and no effort is needed 

 but the primary one of creation. 



