a priori deal only with the methods of molecular biology, but rather that these methods are to be found in many chapters together with the more traditional methods of analysis which have seen recent advances. The numbering of the volumes of the series therefore continues on from 20, which is the most recently published volume under the title Modern Methods of Plant Analysis. As indicated for previous volumes, the methods to be found in Molecular Methods of Plant Analysis are described critically, with hints as to their limi­ tations, references to original papers and authors being given, and the chap­ ters written so that there is little need to consult other texts to carry out the All authors have been chosen because of their methods of analysis described.