This book contains the majority of the presentations of the Second International Symposium on the Biology of Root Formation and Development that was hcld in Jerusa­ lem, Israel, June 23---28, 1996. Following the First Symposium on the Biology of Adventi­ tious Root Formation, held in Dallas. USA, 1993, we perceived the need to include all kinds of roots, not only the shoot-borne ones. The endogenous signals that control root formation. and the subsequent growth and development processes, are very much alike, re­ gardless of the sites and sources of origin of the roots. Therefore, we included in the Sec­ ond Symposium contributions on both shoot-borne (i.e.,