GREY J)KAKE. 33 



a 



I happened to walk by the river-side, at that 

 season of the year, when tlie May-flies (he means 

 the grey sort) which are a species of Libella, 

 come out of the water, where they lie in their 

 husks for a considerable time, at the bottom or 

 sides of the river, near the likeness of the 

 'Nymph of the small common Libella ^ but when 

 it is mature, it splits open its case, and then, 

 with great agility, up springs the new little ani- 

 mal, with a slender body, four blackish veined 

 transparent vvings, with four black spots on the 

 upper wings, and the under wings much smaller 

 than the upper ones, with three long hairs in its 

 tail. The husks which are left behind, float in- 

 numerable on the water. It seemed to me a 

 species of Ephemera ; and I imagined it was 

 the same insect described by Goedart and Sioam- 

 merdam, but a few days convinced me to the 

 contrary ; for I soon found them to be of a 

 Jonger duration than theirs. The first business 

 of this creature, after he is disengaged from the 

 water, is flying about to find out a proper place 

 to fix on, as trees, bushes, 8cc. to wait for ano- 

 ther surprising change, which is effected in a 

 few days. The first hint I received of this 

 wonderful operation, was seeing the Exuviae 

 hanging on a hedge : I then collected a great 

 many, and put them into boxes, and by strictly 

 observing them, 1 could tell when they were rea- 

 dy to put off their husks, though but so lately 

 put on. 1 had the pleasure to shew my friends 

 one that I held in my hand all the while it per- 

 formed this great work. It is surprising to see 

 how easily the back part of the fly split open, 

 and produced the new birth ; which 1 could not 

 perceive partakes of any thing from its parent, 

 but leaves head^ body, wings, legs, and even its 



