THE STONE-FLY. 



493 



their preliminary stages of existence. In the larval and pupal states, they are inhabitants 

 of the water, and are fond of hiding themselves under stones, or burrowing into the muddy 

 banks. Under the latter circumstance they make a very curious tunnel, something like 

 a double-barrelled gun. It is said that the larva feeds upon mud, and, as a proof of this 

 assertion, it may be mentioned that Swammerdam always found mud within those 

 specimens which he dissected. I can personally vouch for the accuracy of his remarks, 

 but would not like to assert that, although mud was always found in the stomach and 

 intestines of those larvae which I have dissected, it might not have been swallowed with 

 the food rather than composed it. 





ANT-LION. Myrmeleor* 

 MAY-FLY. Ephemera vulgata. 



The May-fly is peculiarly notable for a stage of development which seems to be quiie 

 unique among insects. When it has passed through its larval and pupal state, it leaves 

 the water, creeps out of its pupa case, and takes to its wings. After a period, varying 

 from one to twenty hours, it flies to some object, such as the trunk of a tree or the stems 

 of water-plants, and casts off a thin membranous pellicle, which has enveloped the body 

 and wings, the dry pellicle remaining in the same spot, and looking at first like a dead 

 insect. After this operation, the wings become brighter, and the three filaments of the 

 tail increase to twice their length. Some authors call the state between the leaving the 

 water and the casting the pellicle the " pseudimago " state. 



Some of these insects are well known to fishermen under the names of green and grey 

 drake, the former being the pseudimago, and latter the perfect form of the insect, which 

 is represented in the illustration. Sometimes these insects occur in countless myriads, 

 looking like a heavy fall of snow as they are blown by the breeze, and having on some 

 occasions been so plentiful, that they have been gathered into heaps and carted off to the 

 fields for manure. 



The Perlidse, known to anglers by the name of STONE-FLIES, belong to the Neuroptera. 

 Several species of the same family are popularly called Yellow Sally and Willow-fly. 



