8 INSTINCT. 
or llama before they enter on the deserts, and 
which enable them subsequently to subsist 
without water for many days. 
But the instincts by which animals are en- 
abled to search for and obtain food may be 
easily sup to be much more numerous 
and varied than those by which they merely 
seize and swallow it, and in fact furnish the 
conditions by which the varieties of the whole 
Structure of animals are chiefly determined. 
Probably the greatest number of animals are 
nourished by the vegetable world ‘in the living 
or dead state, and are continually guided by 
sensations, to which instinctive efforts are at- 
tached,—i. e. by appetites,—in the selection of. 
food, which may in general be found and 
seized without much difficulty. But through- 
out the whole animal kingdom, from the mi- 
croscopic animalcules up to the largest of 
the Mammalia, a very great number of carni- 
vorous animals are found, who subsist on, and 
continually repress the numbers of, the herbi- 
vorous tribes; and. it may easily be supposed 
that the instincts implanted in these animals, 
which oppose and counteract the varying efforts 
at self-preservation already mentioned, will be 
more varied, and bear more marks of contri- 
vance and ingenuity. Accordingly, from the 
numerous Vorticelle, or other animalcules, of 
the order Rotatoria, which excite currents in 
the water around them, and so attract into 
their stomachs many of the smaller ani- 
malcules, up to the lion, the whale, or the 
eagle, we find an infinite number of con- 
trivances and instinctive me aC served 
by organs, by which the predaceous animals, 
of all the orders, are enabled to prey on the 
others. The Polype, Echinus, and Actinia, for 
example, among the Zoophyta, seize their 
prey, as it is brought to them by the waves, 
with their numerous tentacula; the Entozoa, 
and the leech and other of the Annelides, have 
the faculty and the necessary instinct of attach- 
ing themselves to the larger animals in the 
situations which suit them, as the Cirrhipedes 
or barnacles do to vegetable substances. The 
cuttle-fish and other predaceous Mollusca have 
legs furnished with admirably constructed 
suckers and powerful jaws, and most of the 
Crustacea have claws and mandibles, suf- 
ficient to enable them to seize and destroy ma- 
rine animals of very considerable size ; and it 
is unnecessary to enlarge on the powerful 
means of destruction, or on the instincts guid- 
ing their use, which are seen in many genera 
of each of the classes of vertebrated animals. 
There is often a peculiar instinct guiding 
each of the Carnivorous Mammalia to the 
part of the body of its victim where it can 
most easily inflict a mortal wound, to the 
throat in the case of a large animal, to the head 
in that of a small one, of which the cranium 
may be pierced. In the greater number of 
them, however, the instinctive actions by which 
their prey is obtained are distinguished only by 
power and violence ; and although much con- 
trivance is employed for adapting the different 
parts of the structure to the habits and des- 
tination of the animals, there is little apparent 
ingenuity in the modes in which the animals 
perform their office in creation. The attitud 
and gesture of the cat, the pointer, or the tiger, — 
slow stealing with crouched shoulders on — 
his prey,” is an example of instinctive con-— 
trivance preliminary to the act of violence. — 
The aspect and expression of many camivo- ~ 
rous animals,—not only of the Mammalia and ~ 
birds, but of the shark, the cuttle-fish, the 
scorpion, the tiger-beetle, &c., are so adapted 
to the feelings and instincts of the animals on 
which they feed, as often to deprive them of 
the power of flight or resistance; and it is” 
maintained by many, that some of the predace-— 
ous animals have the power of fascinating 
Rr by merely fixing their eyes on them. 
any have ascribed this power to the 
and Mr. Kirby asserts it with confidence of — 
the fox.* A few only of the predaceous ani- 
mals, as the dog and wolf, have the instinct — 
of associating together for pages their prey. | 
It has been stated that the pelican the — 
dog-fish have a similar instinct.+ o 
But the more striking indications of con- 
trivance in the actions prompted by in- 
stinct are to be found in some of pow- 
— of the carnivorous sale ius 
iscatorius or fishing-frog, al a 
fish, having no strength or speed, obtains its — 
prey by stratagem, plunging itself in mud, or 
covering itself with sea-weed: “ it lets no part 
of it be perceived except the extremity of the 
g 
pear like worms. The fishes, attracted by this — 
apparent prey, approach and are seized bya 
single movement of the fishing-frog, and swal- 
lowed by his enormous throat, and retained by — 
the innumerable teeth by which it is armed.” f _ 
A still more singular art is practised by the 
Cheetodon rostratus, which feeds on pili, 
as Sir Charles Bell states, actually takes aim 
at them, and shoots them with a drop of water.§ 
The instinct of the myrmecophaga or ant-eater, — 
which protrudes the tongue to allure flies to 
settle on it, and then suddenly retracts it to 
devour them, also deserves notice. A more — 
complex art is practised by the ant-lion, which — 
digs a pitfall in the track usually followed by — 
ants, and conceals itself in the bottom of it, — 
waiting for its prey. But of all contrivances - 
in the animal creation for procuring food, the 
most complex and artificial are those of the — 
different genera of spiders, equally curious on — 
account of the peculiar organs by which they — 
spin their webs, as of the peculiar and varied — 
instincts by which they are guided in» “4 
them.|| For example, “ any common black — 
and white spider (Salticus Scenicus), which — 
may always be seen in summer on sunny rails, — 
&c., when it spies a fly at a distance, ap- — 
proaches softly, step by step, and seems to 
measure his distance from it by the eye; then 
if he judges that he is within reach, first fixing 
* Vol. ii. p. 269. 
t See Darwin’s Zoon. vol. i. p. 229, 249. 
¢ See Kirby, vol. ii. p. 406, and pl. xiii. 
i Bridgewater Treatise, p. 200. 
| See Kirby, vol. ii. p, 184 and 286. 
