1893.] The Gases in Living Plants. 5 
It was over thirty years before a work of importance in this 
line again appeared. In 1837 Dutrochet published his ana- 
tomical and physiological memoirs, in which he carefully 
studied the structure of vegetable organs as well as their 
functions. He was the first to rightly point out the relations 
of the cavities in plants to the movement of gases in respira- 
tion, that only cells with chlorophyll are able to decompose 
carbon dioxide, and to distinguish sharply between respiration 
and assimilation. But although he recognized the essentially 
different character of the two processes, respiration and assim- 
ilation, yet he used the erroneous and absurd nomenclature of 
the time, and called them nocturnal and diurnal respiration. 
The weight of his example did much to fix the terms in popu- 
lar usage, where they still persist, in spite of the protests of 
every ableinvestigator and writer upon the subject since; and 
even though the matter was set right by Garreau in 1851, who 
did admirable work upon plant respiration. 
In 1865 appeared the handbook of experimental physiology 
of plants by Julius Sachs, the founder of the modern school 
of vegetable physiologists. The work was comprehensive, 
well balanced, and replete with clear ideas of the theoretical 
bearing and logical association of the facts. 
The author’s laboratory at Wiirzburg, where he shortly 
became established, has been the school from which most of 
the great plant physiologists of the present have received 
instruction and from which all have drawn inspiration. It is 
sad that its doors should now be darkened by the mists that 
have gathered over the intellect of its honored director. 
In the handbook of Sachs a chapter is devoted to each of ` 
the three branches of the subject; aeration, or the movement 
of gases in the plant; respiration, or the action of atmos- 
pheric oxygen; and the effect of light upon vegetation, chiefly 
in assimilation. Each of the os is treated in a clear and 
masterly manner. 
NATIONALITY OF DiscOVERERS AND WRITERS. 
Having traced the growth of knowledge regarding the vital 
relations of gases to plants up to the time when it was possible 
