NATURAL HISTORY. 33 
supple, and then to wash out the black pulp 
(pigmentum nigrum), with a camel’s-hair pencil, 
when they may be mounted.* 
To give a description of all the minute parts 
of this larva that would interest a true lover of 
Nature would occupy a volume. I cannot, 
however, omit to notice the singular structure 
of the bristles which adorn their feet. They 
are branched, or serrated, like those on the 
bodies of certain flies (syrphi) and plants, a 
beautiful example of which is afforded on the 
petals of the flower of the scarlet chick-weed. 
In the Libellula their form is constantly the same 
in similar parts; hence, we may infer, they per- 
form a specific office. Thus those about the 
joint, at a, plate 3, are strong tridents, without 
any serratures or spines; while those that bor- 
der the next joint, b, are formed in the curious 
manner shewn in the annexed figure, which is 
a highly magnified view. 
The trident hairs lie on the inferior side of 
* It appears, from some recent dissections of compound 
eyes, that the plates which compose the cornea are distinct 
lenses, each capable of forming an image; a tube is placed 
behind them, and another lens at the opposite end. A favour- 
able example of this construction is the pedunculated eye of the 
Craw-fish and Lobster. It is difficult to find a subject more 
interesting for microscopic investigation than the dissections of 
compound eyes. 
c 3 
