Excerpt from The Bio-Chemical Journal, 1909, Vol. 4 Experimental evidence of this persistence of relationship to light of all cells exists of two kinds; there is first the deleterious effects of complete withdrawal of light for prolonged periods, and the necessity of sunlight. For healthy existence; and, secondly, there is the direct evidence of the effects of application of strong light to animal cells seen in the Finsen effects, and in other forms of radiant energy allied to light. It is, however, in the more lowly organized types of both animal and vegetable organisms that the strongest and most direct reactions to light are observable - apart from the particular case of the reaction of chemical synthesis in the chlorophyll-containing cells of the green parts of the higher plants. Examples of this reactivity are seen in the effects of sunlight upon nearly all types of bacteria; in the sudden outburst of vegetable life in the form of diatoms in the spring of each year as the length of the day increases and the more vertical light reaches and penetrates the water before there is much increase in the temperature of the sea - an outburst upon which the whole life of the sea is as thoroughly dependent as that of the terrestrial world is upon the similar outburst of activity in land plants; and in the most marked movements which occur towards or from the light according to varying circumstances of the minute organisms, either larval or adult, which chiefly constitute the plankton or floating life of the ocean. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.