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A technique is described for the production of carbon negative replicas for electron microscopy, which has revealed the same type of ultraestructure observed by other authors, on leaf surfaces of the Brassica oleracea. The procedure follows: 1) deposition of a carbon film over the surface of the leaf to be studied; 2) the carbon film is then backed with Zapon Acquanite "A" lacquer as intermediate replica, whichmis applied full strenght over the specimen surface and dried before a heat lamp; 3) the carbon-zapon composite film can be stripped from the leaf with no dificulty whatsoever, and is them metal shadowed; 4) the composite film is placed, carbon side down, on a specimen screen and this placed upon a course wiremesh back in a petri-dish. Amyl acetate as solvent for the zapon is added until it just wets the support screen and the dish is covered. Thus the zapon is dissolved by the condensed amyl acetate vapors. The method has, also, allowed to observe that in the Coffea arabica leaf surfaces the characteristics ultrastructure does not present the microprojections found on the Brassica oleracea.

O presente trabalho apresenta um método de réplica de superfície para o estudo da estrutura das fôlhas de vegetais ao microscípio eletrônico. O método permitiu a observação do mesmo tipo de estrutura observada por outros autores na superfície das fôlhas de couve (Brassica oleracea). O método permitiu observar que nas superfícies das fôlhas de café (Coffea arabica) a ultraestrutura característica e pràticamente desprovida do tipo de ornamentação encontrado nas fôlhas de couve.