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This article informs that thirteen fossil Erica-type seeds extracted by D.G. Wilson from samples collected from the Cromer Forest Bed Series at Pakefield, Suffolk, and Beeston, Norfolk, were examined in the Cambridge Stereoscan Mark II scanning electron microscope at the New University of Ulster. Of the thirteen fossil seeds examined under S.E.M. five were assigned with varying degree of certainty to Erica lusitanica. They could be distinguished from Bruckenthalia spiculifolia on the basis of the characteristics already noted. One seed was tentatively identified with Erica tetralix L., though poor preservation made confirmation impossible. All but one of the remainder were too poorly preserved to permit confident identification.

Unpollinated, cross-pollinated and self-pollinated stigmas of Brussels sprouts and kale were examined in a scanning electron microscope as fresh uncoated specimens. The stigmatic papillae are closely appressed in young stigmas, but are held apart in the mature stigma by the swollen bases of the papilla cells. Some self-pollen tubes show obvious signs of inhibition by being very short, or by coiling over the surface of the papilla without penetrating it. Other self-pollen tubes appear to behave like cross-pollen tubes by producing tubes which penetrate papillae directly. The implications of these observations for the identification of the site of the incompatibility reaction are discussed. [ABSTRACT FROM AUTHOR]

The morphology of the inner and outer surfaces of cuticular membranes of mono- and dicotyledonous leaves and fruits was studied with the scanning electron microscope. Variations in surface structure are related to differences in thickness and composition of the membranes. Delicate leaf membranes have fine ridges and simple stomata, well-developed membranes, thick V-shaped ridges and heavily cutinized stomata. Fruit membranes show deep ridges and extensive secondary cutinization. The most heavily cutinized structures occur in membranes which yield high proportions of 10, 16-dihydroxyhexadecanoic or 9,10,18-trihydroxyoctadecanoic acid which suggests that the membrane thickness and the complexity of the structural features are associated with the degree of hydroxylation of the constituent cutin acids. The relationship between the structure and composition of the cuticular membrane and the type and growth habit of the plant is discussed. [ABSTRACT FROM AUTHOR]