MICROSCOPIC DRAWING AND ENGRAVING. 
transmitted through it. The colour of the head is then a strong 
Indian yellow, with darker shadings of a bright chesnut. The 
eyes are a brilliant carmine; its covering of hairs is more sparse 
than when it arrives at maturity; its swimmers or paddles are 
shorter, and its head hears a greater proportion to its body. 
54. The manner in which it deals with its prey, shows extra¬ 
ordinary intelligence ; many of the creatures upon which it feeds, 
being crustaceous, are invested on the head and back with a shell- 
armour, being unprotected on the belly and lower part of the 
body ; when they attract the notice of the larva, the latter accom¬ 
plishes its object by swimming under its intended victim; when 
sufficiently near, turning its head upwards, it seizes its prey, 
between its jointed antennee, A A, fig. 34 ; having thus secured it, 
it stabs it in the belly with its sharp mandibles, B b, so as to disable 
it, it then rises to the surface of the water, and holding its victim 
above the surface, so as to prevent it from struggling, shakes it, 
as a dog would a rat. 
Its next operation is to pierce it with a weapon represented at I), 
which issues from a horny sheath; this instrument, when not 
in use, is withdrawn into the sheath. As shown in the figure, it 
is protruded from the sheath to about three-fourths of its length. 
This curious weapon consists of a piercer and sucker, the one 
giving the wound, and the other drawing the blood or other juices. 
"When from the nature of the part attacked, this weapon fails of 
its purpose, the victim is seized between the serrated hooks of a 
pair of forceps, c c, by which it is torn to pieces, and the juices 
more easily approached by the sucker, d. 
55. When supplied with abundant food, this creature arrives at 
its full growth in three or four months, and is then nearly opaque 
and covered with hair. When caught and kept several days 
without food, its ferocity is greatly increased, so that it will 
attack insects much larger than itself, if supplied to it, and will 
even devour other individuals of its own species. Its prudence 
and intelligence, however, are displayed by studiously avoiding 
those with whom a contest would be dangerous to it, such for 
example as the water-scorpion. 
The eyes are compound, but of a very peculiar formation, con¬ 
sisting of seven oval pupils, arranged like leaves on each side 
of a stem, as shown at E e ; the entire head and chest are curiously 
marked with lines and spots. 
There are three pair of legs, the fore legs e e, the hind legs H h, 
and the middle legs g g ; each leg terminates in a sharp claw. Pro¬ 
jecting from each side of the body are seven swimmers or paddles, 
similar in their position and arrangement, though not in their struc¬ 
ture to those of the larva of the day-fly already described; they are 
84 
