Disease in plants / by H. Marshall Ward.

  • Ward, H. Marshall (Harry Marshall), 1854-1906
Date:
1901
Catalogue details

Licence: In copyright

Credit: Disease in plants / by H. Marshall Ward. Source: Wellcome Collection.

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    instance the production of osmotic pressures in the cell. And, thirdly, part of the synthesised substance is worked up into higher bodies, by processes which obviously entail the further doing of work on the constituents. The further pursuit of this theme would evi- dently carry us beyond the more immediate subject of this book ; but I want to make clear that recent researches render it more and more certain that the living plant is a complex piece of co-ordinated machinery which brings together matter and energy from the external universe, and then gets work out of these. This proposition is the more important because the whole question of the enrichment of our planet with new food, new building materials, and new fuel, to compensate the daily losses, depends on it, and is of course to be referred fundamentally to the acquirement of new supplies of energy from the sun. Enormous activity has been displayed by physiologists, since 1860, in attempting to solve the question, which of the many different rays known to proceed from the sun are absorbed by the chlorophyll-corpuscle, and directed to the performance of the work above referred to. The names of Draper, Sachs and Pfeffer stand forth prominently as pioneers in this ; while those of Lommel, Engelmann, Timiriazeff and Langley have been among the most active in making important contributions to the subject, and in attempting to answer the further questions con-