In the 1870s, as the research ship HMS Challenger passed through the Philippines during its circumnavigation of the Earth, it dredged up a sponge from the gray sludge 95 fathoms (nearly 600 feet) below the surface. The scientists knew that glass sponges abounded in these waters, their bodies fragile, translucent, and curiously geometric. Sponges of this sort often house other animals, such as monogamous shrimp and various worms. So it was not exactly revelatory that the dredged-up sponge contained a worm, but the worm itself was a revelation. It had laced its body through the sponge's many passages, so much so that it might have resembled many worms. But it was just one worm whose body appeared able to branch like a tree. "The body of the annelid appears to have a furor for budding," the zoologist W. C. M'Intosh wrote in an 1879 paper describing the preserved specimen of the worm. Although M'Intosh did not comprehend this at the time, the worm had a furor for budding multiple anuses.