INSECTS.

manner, and in common with kindred creatures, is capable of grasping and twining round objects of almost any shape. Such a structure must be very favourable to the exercise of touch. It has been said of serpents, that their whole body is a hand, conferring some of the advantages of that instrument. The slender tongue is also used for the purposes of touch.

In those species of lizards which are enabled, by the structure of their feet, to clasp the branches of trees, as the gecko and the chameleon, and whose tails also are prehensile, it must be supposed that the sense of touch is greater than in other reptiles, who have not such an advantage.

Insects are variously endowed with the sense of touch. Spiders, for instance, in constructing their webs must use their eyes in planning their frameworks, but they cannot be guided by sight in the details. As the spinneret, from whence their threads. are drawn, is situated behind, they must depend, in a great degree, on the delicate tact of this organ for the accuracy of their work. The claws, also, must have this sense in great perfection, for, in making the various rays, as well as the cross lines of a web, the spider always guides the thread from the spinneret by one of its hind claws, which it cannot possibly see, as

BIRDS.

all its eyes are placed forwards on the head. The harvest spiders, which have only two eyes, and do not spin webs, use their long legs not only to escape from enemies, and to pursue their prey, but to explore by touch the objects among which they travel. The chief organs of touch in insects, however, are the antennæ and palpi.

Antennæ and Palpi.

In looking at birds, it might be supposed, from the scaly covering of their feet, and the feathered surface of the body, that they were not remarkable for the sense of touch. Yet, it is certain that they possess it in a high degree. In them it resides in the mouth, the bill, or the tongue, for which purpose there is a copious supply of nerves. In water-birds, and particularly in the duck-billed animal of Australia, this sense dwells in the coverings of the expanded proboscis of the jaws, particularly the upper, where the nerves are also very abundant. Such a power must be of great importance, to enable them to detect, so easily and certainly, the food for which they have to grope in the mud and water.

THE LION.

The mole is provided with an elongated muzzle, which acts as an organ for seizing its food. In the seal, a long nerve proceeds from below the socket of the eye to be distributed to the projecting lips. This nerve is composed of forty branches or more. The whiskers on a cat's upper lip have frequently been noticed, but the importance of them in a state of nature, has not been as commonly perceived. They are, in fact, organs of touch. As they are attached to a bed of close glands under the skin, and each of these long and stiff hairs is connected with the nerves of the lip, the slightest contact of the whiskers with any object is thus distinctly felt, although the hairs are insensible.

The same provision is made for the lion. The whiskers stand out on each side of the animal as they do in the common cat; so that from point to point they are equal to the width of the lion's body. Let this animal, stealing through a covert of wood in an imperfect light, pass before the eye of the mind, and the use of these hairs will at once appear. They indicate any obstacle to the passage of his body, and preventing the rustle of the boughs and leaves, which would give warning to his prey, enable him to move towards his

PROBOSCIS OF THE ELEPHANT.

victim with a remarkable stillness. In the rhinoceros the soft upper lip is used as the organ of touch.

Perhaps the most remarkable instrument of this kind among inferior creatures, is the proboscis of the elephant. Most admirable is the structure of this instrument. It is composed entirely of bundles of muscular fibres, disposed in order longitudinally and transversely, and enclosing two canals. These canals are for the purpose of drawing up water, to be afterwards discharged into the throat, or over the body at pleasure. They are, in fact, two self-acting syringes. The num

Extremity of the Proboscis, showing the Finger and Thumb,
with the Canals.

ber of distinct muscles with which the trunk is furnished, each having its distinct action, is not far short of forty thousand. By their contraction or relaxation they are capable of drawing up, shooting out, or twisting in direction the instrument they compose. any