3 There are other trends in the attempt to meld evolution and development which immodesty permits me to add. I have been concerned over the years with the selection forces which might have produced larger organisms and therefore a development of increasing complexity. This is nowhere more evident than in the multiple evolutionary origins of multicellularity and all the variety of developmental mechanics that have gone with it. (I discuss this and related themes in various places, but see especially The Evolution of Development (1958; (1)) and Size and Cycle (1965; (2)). To some degree these examples of the bringing together of evolu tion and development are exceptions. By far the most important historical trends in this century have been the success of in dividual disciplines. Embryology had its great flowering be ginning in the last century, coming to a climax with the work of Spemann on induction in the first two decades of this cen tury. Genetics has had an extraordinary continuing series of revolutions beginning with the rediscovery of Mendel and pro gressing through Morgan to the flash flood of molecular genetics and the structure of DNA. This flood was a flash only in the sense that it rushed upon us with amazing speed; its effects in the form of important and exciting work produced has not subsided and we are still in a peak period of molecular genetics."

The chemistry of condensed tannins has hitherto represented a relatively unattractive and therefore neglected area of study; one in which the weight of research effort involved is invariably disproportionate to the results achieved, in which the participating schools generally confine their approach to specific molecular species, and in which as yet no consensus has been reached regarding likely precursors. The problems which beset those engaged in this field represent a combined function of the abnormal complexity of the gradational range of oligomers of increasing mass and affinity for substrates which typify most extracts rich in tannins, and the consequent problem of their isolation and purification, the high chirality of tannin oligomers, the need to contend with the phenomenon of dynamic 'rotational isomerism about interflavanoid bonds in the IH n.m.r. spectral interpretation of their derivatives, the lack of precise knowledge regarding the points of bonding at nucleophilic centres, and the obvious limitations of a hitherto predominantly analytical approach. The last of these reflects the need for a general method of synthesis which permits unambiguous proof of both structure and absolute configuration also at higher oligomeric levels. With these objectives in mind we initiated a purely synthetic approach based on the premise that flavan-3,4-diols as source of electrophilic flavanyl-4-carbocations, and flavan-3-0Is as nucleophiles (cf 1,2) represent the prime initiators of a process of repetitive condensation in which the immediate products also represent the sequent nucleophilic substrates.