THF WORM. 



559 



destitute of feet, trail themselves along upon 

 Ihe ground, and find themselves a retreat 

 under the earth, or in the water. As these, 

 like serpents, have a creeping motion, so 

 both, in general, go under the common appel- 

 lation of reptiles : a lothesome, noxious, ma- 

 lignant tribe, to which man by nature, as well 

 as by religion, has the strongest antipathy. 

 But though worms, as well as serpents, are 

 mostly without feet, and have been doomed to 

 creep along the earth on their bellies, yet their 

 motions are very different. The serpent, as 

 has been said before, having a back-bone, 

 which it is incapable of contracting, bends its 

 body into the form of a bow, and then shoots 

 forward from the tail ; but it is very different 

 with the worm, which has a power of contract- 

 ing or lengthening itself at will. There is a 

 spiral muscle, that runs round its whole body, 

 from the head to the tail, somewhat resembling 

 a wire wound round a walking-cane, which 

 when slipped off, and one end extended and 

 held fast, will bring the other nearer to it; in 

 this manner the earth-worm, having shot out, 

 or extended its body, takes hold by the slime 

 of the forepart of its body, and so contracts and 

 brings forward the hinder part; in this man- 

 ner it moves onward, not without great efforts; 

 but the occasions for its progressive motions 

 are few. 



As it is designed for living under the earth, 

 and leading a life of obscurity, so it seems to- 



render them, in some degree, indestructible. The gen- 

 erality of the intestinal worms of animals, and, the sepife 

 excepted, by far the greater number of worms, are true 

 hermaphrodites, of which each individual is capable of 

 propagating the species. The mode of copulation in 

 many animals of this class is also very peculiar, as in the 

 common garden and tree snails, which at that time are pro- 

 vided with a remarkable little dart, composed of calcareous 

 matter, and having the shape of a four-edged lance. This 

 dart is fixed loosely in an opening in the neck, and when 

 the two snails meet, each presses its dart into the breast 

 of the other, this mutual excitement being precursory to 

 actual copulation. 



" The vast numbers of marine animals in this class, par- 

 ticularly the testacea and corals, are of extreme impor- 

 tance to the general economy of nature, inasmuch as they 

 in the ocean, in the same manner with insects upon the 

 earth, incessantly destroy, consume, and, as it were, me- 

 tamorphose an infinite variety of noxious or superfluous 

 substances. To man, they are in so far serviceable, that 

 many, particularly of the mollusca and testacea, are eat- 

 able; some, as for instance, the venus mercenaria, and 

 mytilus bidens, serving as a principal article of diet to 

 many navigators and inhabitants of sea coasts. The 

 purple dye was procured from certain shell-fish, more for- 

 merly than at present. Ink and Indian ink are procured 

 from the peculiar fluid of the cuttle-fish. The beard of 

 certain species of pinna affords a kind of brown silk, which 

 may be manufactured. Many kinds of shells contain 

 pearls. Red coral is an important article of trade, par- 

 ticularly in the East Indies. Several kinds of shells, 

 either entire or divided, pass current as money among 

 some remote nations. From portions of similar shells, 

 the Iroquois and other North American people, made 

 tneir wampum, which serves the purpose of records. 



lerably adapted to its situation. Its body is 

 armed with small stiff sharp burrs or prickles, 

 which it can erect or depress at pleasure ; un- 

 der the skin there lies a slirny juice, to be 

 ejected as occasion requires, at certain perfora- 

 tions, between the rings of the muscles, to 

 lubricate its body, and facilitate its passage into 

 the earth. Like most other insects it has breath- 

 ing holes along the back, adjoining each ring; 

 but is withoutbones, without eyes, without ears, 

 and properly without feet. It has a mouth, and 

 also an alimentary canal, which runs along to 

 the very point of the tail. In some worms, 

 however, particularly such as are found in the 

 bodies of animals, this canal opens towards the 

 middle of the belly, at some distance from the 

 tail. The intestines of the earth worm are 

 always found filled with a very fine earth, 

 which seems to be the only nourishment these 

 animals are capable of receiving. 



The animal is entirely without a brain, but 

 near the head is placed the heart, which is 

 seen to beat with a very distinct motion, and 

 round it are the spermatic vessels, forming a 

 number of little globules, containing a milky 

 fluid, which have an opening into the belly, 

 not far from the head ; they are also often found 

 to contain a number of eggs, which are laid in 

 the earth, and are hatched in twelve or four- 

 teen days into life, by the genial warmth of 

 their situation; like snails, all these animals 

 unite in themselves both sexes at once ; the rep- 



Many savage people use muscle and snail shells for drink- 

 ing vessels, spoons, Etc. The South sea islanders make 

 from them ingenious hooks and a variety of other fishing- 

 tackle. The North-western Americans point their har- 

 poons with angular pieces of muscle shells. In regard 

 to works of art: mother of pearl and many muscle and 

 snail shells are cut like onyx into camoes. The cuttle- 

 fish bone is employed by artists and workmen. Sponge 

 serves a variety of domestic purposes. Madrepore is 

 employed for paving and building on the coasts of the 

 Red sea. Numerous testacea (the shells) and corals 

 are burnt for lime. Some large thin shells are used as 

 glass in the south of China, and in India. The shells of 

 testacea are among the most common ornaments of sa- 

 vage nations. In the great collection of objects from 

 the South seas presented to the academical Museum of 

 Gottingen, is, among other articles, a necklace of neat 

 shells, carefully polished, bored, and ingeniously twisted 

 together with tendons, all the work of a race of men com- 

 monly considered as the most wretched outcasts of the 

 human species, viz. the natives of the Sierra del Fuego. 

 Lastly, the leech is of great importance in the treatment 

 of certain diseases. (See an account of the leech in the 

 present volume, page 467.) 



"Among the noxious animals of this class, are, in par- 

 ticular, the worms of the human body, which either live 

 in the intestines, as the ascurides fseniae, &c., or as the 

 Guinea-worm, immediately under the skin. Others of a 

 similar character, are the flukes found in sheep, the hy- 

 ditids of swine, and the worms found in many quadru- 

 peds and fishes, producing disease. Earth-worms and 

 snails are injurious to plants. Certain species of the 

 genera teredo and pholas perforate ships and dams." 

 Blumenbach. 



