EPHEMERA. 
^^51 
swarms are produced every season in the neigh- 
bourhood of some particular spots in the Dutchy 
of Carniola, that the countrymen think they obtain 
but a small portion, unless every farmer can carry 
olf about twenty cart-loads of them into his fields, 
for the purpose of a manure*. 
But, of all the European Ephemeras, that which 
has been most celebrated, and of which almost 
every reader must recollect the general and super- 
ficial account so often detailed in works of Natural 
History, is the species described by Swammer- 
dam f. It is of a white colour, with the anterior 
rib of the upper wings black or deep-brown, and 
the tail is furnished with two long bristles. This 
insect, which is common in many parts of Europe, 
is commemorated as a most remarkable instance 
of the brevity of animal life; since after its change 
into the perfect animal it survives but a very few 
hours, perishing in the course of the same even- 
ing that gave it birth. It is to be recollected 
however liiat its larva lives in its aquatic state 
two, and even sometimes nearly three years; and 
is in this state so tenacious of life that Swammer- 
dam assures us that one which he pierced with a 
pin to a board, in order to preserve it, lived all 
* It is necessary to give the words of the author himself. 
What particular kind of vehicles he intended by the word currus 
I know not. Junio mense tanta copia circa Laz Carniolac 
conspicua, ut rustici exiguam messem se coUegisse putent, nisi 
singuli ultra zo currus ea onustos in agrum exoneraverint, cujus 
stercorationi optime insertit.” 
f Ephenio'a horariu ? ? Lin. 
