Observations on motion of captured particles, films of ciliary motion during particle capture, and physical theories of the motion of particles and water contradict substantial parts of Dr. Gilmour's accounts of ciliary feeding by hemichordates and lophophorates. (T. H. J. Gilmour. 1982. Feeding in tornaria larvae and the development of gill slits in enteropneust hemichordates. Can. J. Zool. 60. This issue.)