While there have been many recent books on the cell surface and a few on the topic of cilia and flagella, this is the fIrst volume that attempts to bring together the available informa- tion on ciliary and flagellar membranes. This reflects a slow awakening by cell biologists and other scientists to the signifIcance of ciliary and flagellar surfaces. When Michael Sleigh edited an excellent book entitled Cilia and Flagella in 1974, t one of the sixteen chapters was devoted to ciliary or flagellar surfaces. When W. B. Amos and J. G. Duckett edited the very fIne 25th Symposium of the Society for Experimental Biology on Prokaryotic and Eukaryotic Flagella in 1982, only two of the twenty chapters on eu- karyotic cilia and flagella were devoted to ciliary and flagellar surfaces. Only in 1989 has the timing become right to produce a volume entirely devoted to the naxonemal struc- tures and functions of eukaryotic cilia and flagella. The fIfteen chapters in this volume cover a wide spectrum of organisms (from protozoa and algae to birds and mammals) and an equally wide spectrum of topics (from sexual interactions in the algae to the binding of pathogens in the lung).