There are, however, widely differing degrees of artistry among the tube-dwelling polychaetes. Some tubes are rough, fragile, long, bent in various directions, and united in colonies several inches to a foot across. Sometimes tubes three to four inches long are attached horizontally to the undersides of rocks.
A large and singular terebellid is Amphitrite ornata—twelve to fifteen inches long with orange-brown tentacles capable of being extended eight to ten inches. These are kept in constant motion gathering food and material for building. The bodies of these worms are filled with blood, but there is no circulatory system. The blood, however, apparently can be forced into any part of the body by muscular contractions. The tentacles can be turned voluntarily in any direction by forcing blood into them.
Tube-building, flowering worms excited the wonder of Quatrefages as he observed them along the Bay of Biscay in the nineteenth century:
“On these coasts so violently beaten by waves we often observe small hillocks of sand pierced by an infinite number of minute openings. These little hillocks which look very much like thick pieces of honeycomb are in reality populous cities in which live in modest seclusion tubiculous annelids, the hermellas—(sabellarids) as curious as any that fall under the notice of the naturalist. The body, about two inches in length, is terminated in front by a bifurcated [two-forked] head bearing a bright double golden crown of strong, sharp silk threads. These brilliant crowns are not mere ornaments, but are the two sides of a solid door, or rather true portcullis, which hermetically closes the entrance to the habitation when, at the least alarm, the worm darts with the rapidity of lightning within its house of sand.
“From the edges of the head of this worm issue fifty to sixty slender, light-violet filaments which are incessantly moving about like numerous minute serpents. They are so many arms which can be lengthened or shortened at will and which, seizing the prey as it passes, bring it to the hollow, funnel-shaped mouth. On the sides of the body appear little projections from which issue bundles of sharp and cutting lances. Finally, the back is covered with cirrhi, recurved like circles, whose color varies from dark red to deep green.”
Most conspicuously flowerlike among the worms are the serpulids—“little snakes.”
Found the world over, they furnish passable imitations of practically all the flowers in an old-fashioned Virginia garden. Among them, for example, are the animals of inshore South African waters, described by Prof. McIntosh. Their wreaths of branchia “look like pinks, but in some varieties are purple at the base, with narrow bands of bright red and pale green. In one variety the blossoms are yellow or orange and the body is usually greenish-yellow.” “The instant it is disturbed,” McIntosh says, “this worm withdraws its lovely wreath into its tube and closes the aperture with a curious plug, funnel-shaped and placed at the end of a rather long pedicle.”
The Rev. D. Johnston describes a British flower worm (one of the sabellids) about an inch long, whose eight-inch-long tubes grow together, attached at the bottom to a stone or abandoned shell. The tube has a silk-like lining.
“Into this tube,” says Johnston, “it can withdraw with lightning-like rapidity when alarmed. Extending across its back is a row of microscopic hooks, or 14,000 to 15,000 teeth. These are used to catch the lining of the tube and draw the worm back.”
The filaments which form its blossoms, he says, are comb-like, arranged in two rows, one on each side of the mouth. They form a coronet. Under low magnification each is seen as a pellucid, cartilaginous stem from one side of which springs a double series of secondary filaments through which red blood can be seen flowing.