0Ur may house three dozen teredos, recumbently sharing the space as ln a crack den. Sellius championed his creature's nondisputatious nature, Jeffreys tells us, arguing that the shipworm, while not of a sociable habit, "is actuated by a conscientious anxiety not to infringe on its neighbor. When a collision is imminent, it secretes a cupshaped dome or plug in front, of a thinner texture than the rest of its sheath; and it shuts itself up. Sometimes it makes several of these outer walls, one after another. It then, being unable to eat its way through the wood and thus procure a supply of food, dies of starvation, preferring suicide to the alternative of invading and injuring its companions!" Sellius ascribed a fine sense of honor to his "hero," as he called the teredo. Whether the shipworm disdains to engage in territorial disputes out of chivalry or morose selfabsorption remains an open question. That it is not always so pacific may be seen by the testimony of a later observer, Clapp (1951), who recorded the actions of one shipworm species, not sure whether he was witnessing fighting or copulation: This probing and tearing activity of the excurrent siphon is quite violent. The siphon arches and waves wildly in all directions with gyrations which might be likened to those of the trunk of a very active miniature elephant. ... In spite of the struggles of the incurrent siphon, the excurrent siphon generally eventually succeeds in pushing the tip end for a considerable distance down the inside of the incurrent siphon and is able to maintain a firm attachment there. After a few seconds, active resistance by the incurrent siphon ceases, and the excurrent siphon may then remain in this position for several minutes. During this period, a minute amount of a somewhat transparent fluid may clearly be seen though the transparent walls of both siphons, being ejected spasmodically from the excurrent siphon into the incurrent siphon. This sounds like sex to me. Unfortunately, we have no way of knowing if there was any sperm transfer, because Clapp did not collect the transparent fluid. Those who are interested in such matters may consult another paper, "Sexual rhythm in the pelecypod mollusk Teredo," by Wesley Roswell Сое. As Sigerfoos first postulated, the shipworms sexuality is protandrous, which means it is hermaphroditic, metamorphosing from a male to a female in the course of its development. In shipworms, the female always more mature than the male. Propagation may occur in three ways: () both sperm and eggs are released into the water by the individual in vast numbers (100 million eggs in one spawning), and the pairings allowed occur as they may; (2) the sperm may be extruded into the water and then stored in the gills of the individual, where fertilization subsequently takes place; or (3) an excurrent siphon of a male may eject semen directly into the incurrent siphon of a female, as vividly described by the eminent Clapp, above.