ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1931.tb00596.x

出版商:Blackwell Publishing Ltd    

年代:1931

数据来源: WILEY

摘要:

Summary.1The tissues of the fossil fernAnkyropteris corrugatashow well‐marked reactions to wounding.2In the root these, which consist of irregularly disposed wedges of meristematic tissue, are confined to the cortical parenchyma and may extend for some distance beyond the actual wound area.3In the stem the wounds generally take the form of irregular cortical fissures. These are bordered on either side by a strip of meristem four to eight cells in depth.4Anomalous secondary xylem which occurs in a stem in the neighbourhood of a bifurcation is also considered to be due probably to traumatic stimulus.5In the petiole the wound reaction varies.6Where the wound is superficial a pad of healing meristem is developed from the cortical cells. The parenchymatous cells are most active, but the sclerenchymatous cells may also undergo division. Exceptionally the superficial cells may be modified in a similar way to those of the normal epidermis, thus providing an example of “restitution.”7Other wounds, termed “crush” wounds, are characterised by irregular cortical fissures. These become bordered or surrounded by a strip of meristematic cambiform cells.8Where the wounds are deep‐seated the vascular tissues may be involved in the reaction.9The reaction in such cases takes the form of the development of secondary tracheids, usually short and of small calibre, which vary in position with that of the wound.10There is some evidence that the phloem or phloem‐parenchyma may also become meristematic under the

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1931.tb00597.x

出版商:Blackwell Publishing Ltd    

年代:1931

数据来源: WILEY

摘要:

Summary.There is a strong family resemblance between the cuticles ofRhodomyrtusandTristania, but the latter more frequently has isodiametric stomata and a larger number of narrow and very distinctive girdling cells encircling the guard‐cells. There is, moreover, relatively less parenchyma and there are more stomata per unit of area inTristaniathan inRhodomyrtus. The presence of two genera belonging to such a typical Southern Hemisphere family as the Myrtaceae in the Eocene of Bournemouth is a point of some interest. This investigation is not, however, the first to demonstrate their presence in Europe, for Mrs. Reid (1930) has described fruits and seeds ofRhodomyrtusfrom Tertiary beds of St. Tudy, Finistère, and the latter flora is also regarded as of Eocene age.A cluster of fruits referred toTristanitesby Saporta has been found in the Oligocene of France. He also figures a leaf, and points out that, though its connection with the fruiting branch is doubtful, it agrees in form and venation with the recent genusTristania. Schenk referring to the fossil fruits described by Saporta says that as far as one can judge from their external characters they show decided relationship to the Myrtaceæ. I know of no other fossil records of these genera except of two species ofTristanitesrecorded by Deane from the Miocene flora of Berwick, Austra

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1931.tb00598.x

出版商:Blackwell Publishing Ltd    

年代:1931

数据来源: WILEY

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1931.tb00598a.x

出版商:Blackwell Publishing Ltd    

年代:1931

数据来源: WILEY