T11E EPHEMERA. 
SOI 
Indeed, we must not attend to the rigour of method, in an 
history where nature seems to take delight to sport in variety. 
That there should be a tribe of flies, whose duration extends 
but to a day, seems at first surprising ; but the wonder will 
increase, when we are told, that some of this kind seem to be 
born and die in the space of a single hour. The reptile, how- 
ever, from which they arebred, is by no means so short lived ; 
but is sometimes seen tolive two years, and many times three 
years together. 
All ephemeras, of which there are various kinds, are pro- 
duced from the egg, in the form of worms ; whence they 
change into a more perfect form ; namely, that of aurelias 
which is a kind of middle state between a worm and a fly • 
and thence they take their last mutation, which is into a 
beautiful fly, ot longer or shorter duration, according to its 
kind. 
The ephemera, in its fly state, is a very beautiful winged 
insect, and has a strong similitude to the butterfly, both from 
its shape and its wings. It is about the size of a middling 
butterfly ; but its wings differ in not being covered with the 
painted dust, with which thoseof butterflies are adorned, and 
rendered opaque, for they are very transparent, and very thin. 
These insects have four wings, the uppermost of which are 
much the largest : when the insect is at rest, it generally 
lays its wings, one over the other, on the back. The body 
is long, being formed of six rings, that are larger at the ornnii 
than near the extremity ; and from this a tail proceeds, which 
is longer than all the rest of the fly, and consists sometimes 
of three threads of an equal length, or sometimes of two 
long and one short. 
1 he reptile which is to become a fly, and which is granted so 
long a term, when compared to its latter duration, is an inha- 
bitant of the water, and bears a very strong resemblance to 
ashes, in many particulars, having gills by which it breathes 
•tt the bottom, and also the tapering form of aquatic animals. 
J'hese insects have six scaly legs, fixed on their corselet. 
Their head is triangular; the eyes are placed forward, and 
may be distinguished by their largeness and colour. The 
'pouth is furnished with teeth, and the body consists of six 
'•ngs ; that next the corselet being largest, but growing less 
'nd less to the end : the last ring is the shortest, from which 
be three threads proceed, which are as long as the whole 
>ody. Thus we see, that the reptile bears a very strong re- 
emblance to the fly; and only requires wings, to be very 
'ear its perfection. 
As there are several kindsof this animal, their aurelias are 
consequently of different colours : some yellow, some brown 
