{'fraction_non_alphanumeric': 0.013980263157894737, 'fraction_numerical': 0.005756578947368421, 'mean_word_length': 5.177664974619289, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The changing pattern of research in wood anatomy

Research activity in wood anatomy since 1900 is reviewed with special reference to the pattern of development in (1) descriptive and comparative anatomy, (2) structure in relation to wood properties and (3) the influence of growth on wood structure. In the early decades of the century there was an emphasis on comparative anatomy, often as a contribution to developing the use of the tropical forest resource. At the same time, there was an increasing awareness that an understanding of the behaviour of wood was to be obtained from the study of its physical structure and chemical composition; particular attention has been given to elucidating the structure of the cell wall, at first by conventional optical microscopy and physical techniques and more recently by electron‐ and scanning electron‐microscopy. Studies of the interaction between growth and wood structure have attracted special interest in the post Second World War period and have been prompted by an awareness in many countries for a need to depend increasingly on managed forests as a source of timber and to produce such timbers at minimum cost compatible with acceptable technical performance.