Postprint version. Published in Annual Review of Biophysics and Bioengineering, Volume 13, June 1, 1984, pages 85-103.
NOTE: At the time of publication, the author Richard B. Frankel was not yet affiliated with Cal Poly.
The definitive version is available at http://dx.doi.org/10.1146/annurev.bb.13.060184.000505.
1984 Annual Review.
This article has been accepted for publication by Annual Reviews in a revised form.