MICROSCOPIC DRAWING AND ENGRAVING. 
description, are placed in the membraneous paddles along its sides y 
and the air is imbibed from the surrounding fluid. 
56. After this creature has remained for a considerable time in 
the state of larva, and when it appears to become conscious that 
the epoch of its passage into the second stage of its existence, that 
of chrysalis, is approaching, it issues from the water and proceeds 
to excavate for itself a hole in the ground, in which it undergoes 
the metamorphosis by which it passes into the state of a chrysalis, 
in which it remains for some days, after which it emerges a per¬ 
fect beetle. 
The female bears on each side of the hinder extremity of her 
body a spinning apparatus, which she uses to make the bag i£ 
which her eggs are deposited, and which has been already 
described. 
57. Dr. Goring has also left a drawing of another species of 
dytiscus, called the water-beetle. 
This insect resembles, in the manner of its propagation and its 
habits, that which has been above described. It is carnivorous, 
and of a ferocious and cruel character. If it is placed in a vessel 
with other aquatic insects, it soon devours them. 
A magnified view of it is shown in fig. 35 ; the insect, in its real 
size, being represented in the lower figure. The drawing from which 
this engraving was taken, was made immediately after it had cast 
its first skin, a moment at which its internal organisation is more 
distinctly visible than at any other period of its existence, by 
reason oT the thinness and transparency of its newly-developed 
vessels. Its anatomical structure is more delicate and beautiful 
than that of any other larva of the order of coleoptera, and, 
although its weapons of attack appear less formidable than those 
of the water-devil and some other species, the remarkable manner 
in which its internal functions are rendered visible more than 
compensate for this, when the insect is regarded merely as a 
microscopic object. 
It is armed with a pair of curved mandibles, which move 
horizontally, and are long enough to cross each other when 
closed. They are of a fine nut colour, becoming darker towards 
the points, which are hard and sharp. With these the insect 
seizes its prey, and bringing it towards its mouth, sucks its blood 
after having first pierced it. This it delights to do without 
killing its victim, unless it is constrained to do so, by the superior 
strength of the latter. If it seizes the larva of the gnat, or any 
other tender insect, it brings different parts of its body to its 
mouth, devouring it piecemeal, except the skin, which it rejects. 
If its prey is a strong animal, protected by an external shell, it. 
seizes it, and holds it for some time at rest, until its victim 
86 
