First Published in 1971. Routledge is an imprint of Taylor & Francis, an informa company.

First Published in 1971. Routledge is an imprint of Taylor & Francis, an informa company.

Tropical climates, which occur between 23 Degrees30'N and S latitude (Jacob 1988), encompass a wide variety of plant communities (Hartshorn 1983, 1988), many of which are diverse in their woody floras. Within this geographic region, temperature and the amount and seasonality of rainfall define habitat types (UNESCO 1978). The F AO has estimated that there 1 are about 19 million km of potentially forested area in the global tropics, of which 58% were estimated to still be in closed forest in the mid-1970s (Sommers 1976; UNESCO 1978). Of this potentially forested region, 42% is categorized as dry forest lifezone, 33% is tropical moist forest, and 25% is wet or rain forest (Lugo 1988). The species diversity of these tropical habitats is very high. Raven (1976, in Mooney 1988) estimated that 65% of the 250,000 or more plant species of the earth are found in tropical regions. Of this floristic assemblage, a large fraction are woody species. In the well-collected tropical moist forest of Barro Colorado Island, Panama, 39. 7% (481 of 1212 species) of the native phanerogams are woody, arborescent species (Croat 1978). Another 21. 9% are woody vines and lianas. Southeast Asian Dipterocarp forests may contain 120-200 species of trees per hectare (Whitmore 1984), and recent surveys in upper Amazonia re corded from 89 to 283 woody species ~ 10 cm dbh per hectare (Gentry 1988). Tropical communities thus represent a global woody flora of significant scope.

As 1992 looms on the horizon and preparation is made for the completion of the internal market in Europe, the CMR realised the value of addressing some of the issues involved and defining the objectives and achievements of medicines regulations in a number of EEC countries in comparison with Japan and the USA. The overall aim was to use the lessons of past experience to determine the most appropriate way forward. The final debate focused on two possibilities for assessing and granting marketing authorisations for Europe, namely mutual recognition or a centrally organised European Med icines Office. These two views were discussed in detail at both the workshop at the Ciba Foundation and the international symposium at the Royal College of Physicians. It is hoped that this sharing of ideas and the publication of the proceedings of this fifth CMR Workshop will have encouraged all concerned to continue the debate so that the final outcome will be the establishment of an efficient system in the community for the benefit of patients, the practising physician and the pharmaceutical industry. We would like to take this opportunity of thanking Brenda Mullinger for the considerable amount of scientific and editorial work that she carried out on the manuscripts, Sheila Wright for providing the secretarial support which allowed the proceedings to be submitted to Kluwer Academic Publishers on disk and Sandra Cox who organised the administrative aspects so vital to the successful running of a Workshop and major international symposium. S. R."

Tropical climates, which occur between 23 Degrees30'N and S latitude (Jacob 1988), encompass a wide variety of plant communities (Hartshorn 1983, 1988), many of which are diverse in their woody floras. Within this geographic region, temperature and the amount and seasonality of rainfall define habitat types (UNESCO 1978). The F AO has estimated that there 1 are about 19 million km of potentially forested area in the global tropics, of which 58% were estimated to still be in closed forest in the mid-1970s (Sommers 1976; UNESCO 1978). Of this potentially forested region, 42% is categorized as dry forest lifezone, 33% is tropical moist forest, and 25% is wet or rain forest (Lugo 1988). The species diversity of these tropical habitats is very high. Raven (1976, in Mooney 1988) estimated that 65% of the 250,000 or more plant species of the earth are found in tropical regions. Of this floristic assemblage, a large fraction are woody species. In the well-collected tropical moist forest of Barro Colorado Island, Panama, 39. 7% (481 of 1212 species) of the native phanerogams are woody, arborescent species (Croat 1978). Another 21. 9% are woody vines and lianas. Southeast Asian Dipterocarp forests may contain 120-200 species of trees per hectare (Whitmore 1984), and recent surveys in upper Amazonia re corded from 89 to 283 woody species ~ 10 cm dbh per hectare (Gentry 1988). Tropical communities thus represent a global woody flora of significant scope.