IV. NEUROPTEROUS Have four membranous and semi-transparent wings, veined like net-work; and the tail without a sting, as the _dragon-fly_ and _ephemera_. V. HYMENOPTEROUS Have four membranous and semi-transparent wings, veined like network; and the tail armed with a sting, as the _wasp_ and _bee_. VI. DIPTEROUS Have only two wings, as the _common house-flies_. VII. APTEROUS Have no wings, as the _spiders_. 13. The sixth and last class of animals consists of WORMS, or vermes. These are slow of motion, and have soft and fleshy bodies. Some of them have hard internal parts, and others have crustaceous coverings. In some of the species eyes and ears are very perceptible, whilst others appear to enjoy only the senses of taste and touch. Many have no distinct head, and most of them are destitute of feet. They are, in general, so tenacious of life, that parts which have been destroyed will be re-produced: These animals are principally distinguished from those of the other classes by having tentacula, or feelers. 14. Some late writers have divided the worms into three or more distinct classes; but the Linnæan division is into five ORDERS. ORDERS OF VERMES, OR WORMS. I. INTESTINAL Are simple and naked, without limbs; some of them live within other animals, as the _ascarides_ and _tape-worms_; others in water, as the _leeches_; and a few in the earth, as the _earth-worm_. II. MOLLUSCOUS Are simple animals, without shell, and furnished with limbs, as the _cuttle-fish_, _medusæ_, _star-fish_, and _sea-urchins_. III. TESTACEOUS Are animals similar to the last, but covered with shells, as _oysters_, _cockles_, _snails_, and _limpets_. IV. ZOOPHYTES Are composite animals, and appear to hold a rank between animals and vegetables; though they are in fact true animals, and possess sensation and voluntary motion. In many instances a great number of them inhabit the same stone, but some are soft, naked, and separate. The _coral_, _sponge_, and _polypes_, are instances of this order. V. ANIMALCULES Are destitute of tentacula or feelers, and are generally so minute as to be invisible to the naked eye. They are chiefly found in different infusions of animal and vegetable substances. ---- CLASS I.--MAMMIFEROUS ANIMALS. ---- ORDER I.--PRIMATES. 15. _MAN._ _The only production of the human body which appears to be useful in a commercial view, is the_ hair. Human hair, for the purpose of being made into wigs, and ornamental head-dresses, is imported into this country from the Continent, and chiefly from Germany. We also import hair from China, but the latter is generally of very dark colour. On the Continent this article is almost wholly collected by pedlars, who travel through the different countries, and carry trinkets and other articles for sale, and to exchange for it.