Note 41 — Chapter XI · SEAS OF FLAME.
Reading edition
Page 81. The individual zooids, amounting to many hundreds, are grouped in whorls, their orifices so arranged that the inhalent are upon the outside of the cylinder, and the exhalent upon the interior. Each animal draws in a current from the outside, ejecting it into the interior; the result of this volume of water rushing from the open end being that the entire colony is forced along, at the same time revolving upon its long axis.