EXTRAORDINARY METAMORPHOSIS 113 



probably have died as quickly as do the rest of 

 their species. Yet another quotation, from Kirby 

 and Spence, which will, I feel sure, prove of 

 interest to the reader. 



In vol. iii., p. 296, the writer says : 

 * Some species of the . . . Ephemera are dis- 

 tinguished by another peculiarity, unparalleled, as 

 far as is known, in the rest of the insect world. 

 After being released from the puparium, and 

 making use of their expanded wings for flight, 

 often to a considerable distance, they have yet to 

 undergo another metamorphosis. They fix them- 

 selves by their claws in a vertical position upon 

 some object, and withdraw every part of the body, 

 even the legs and wings, from a thin pellicle 

 which has enclosed them, as a glove does the 

 fingers ; and so exactly do the exuviae, which 

 remain attached to the spot where the Ephemera 

 disrobed itself, retain their former figure, that I 

 have more than once at first sight mistaken them 

 for the perfect insect. You can conceive without 

 difficulty how the body, and even legs, can be 

 withdrawn from their cases ; but you must be 

 puzzled to conjecture how the wings, which seem 

 as thin, as much expanded, and as rigid as those 

 of a fly, can admit of having any sheath stripped 

 from them much less how they can be with- 

 drawn, as they are, through a small opening at 

 the base of the sheath. The fact seems to be 



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