The meaning and usefulness of the phrase "an anatomical space" are question
ed. The concept of anatomical space is examined from historical, developmen
tal, and topographical viewpoints. The validity of the idea and usage of th
e term "potential space" is discussed. The criterion of Haines (1991) is ad
opted, that only "spaces" or "cavities" that are lined with a "mesothelial"
layer and that can repeatedly be opened up without tissue damage should be
considered "true potential spaces." A plea is made that all other anatomic
al "spaces" be designated "compartments." Clin. Anat. 12:66-69, 1999. (C) 1
999 Wiley-Liss, Inc.