RECENT ADVANCES IN SCIENCE 411 



methods of teaching and research adopted in the department to 

 meet modern requirements and the new demand for a rigorous 

 outlook growing up among plant physiologists. The teaching 

 policy of the department is to place teaching as subsidiary and 

 secondary to research. Membership is confined to graduates, 

 preferably from other institutions, and the research is carried 

 out on a general scheme in which all combine on a democratic 

 basis. He points, in the first place, to the double scope of the 

 application of Plant Physiology. In the general application 

 of physiological knowledge to the formation of what may be 

 called a philosophy of the universe, plant physiology, as a pure 

 science, is almost if not quite as valuable as animal physiology. 

 In its practical application, on the other hand, just as animal 

 physiology debouches upon the fields of medicine, surgery, 

 hygiene, animal husbandry, etc., so plant physiology contributes 

 most to human physical welfare in the fields of agriculture, 

 forestry, fermentation operations, bacteriology, etc. Prof. 

 Livingston contrasts descriptive physiology with dynamic 

 physiology, which relates life processes either individually or 

 in their resultant to determining conditions within and without 

 the plant. Owing to the complexity of the processes and the 

 number of the conditions, each operating at so many possible 

 intensities, dynamic plant physiology has remained a largely 

 untrodden field. Methods have for the most part still to be 

 devised. But it is from this, side of plant physiology, which 

 aims at quantitative control, that practical applications will 

 spring. 



The two main aspects of dynamic physiology, upon which 

 attention has so far been concentrated in Prof. Livingston's 

 Laboratory, are the water relations of plants and their inorganic 

 salt relations. The problems involved are the simplest and yet 

 the most fundamental in their bearing upon plant growth, and 

 upon agricultural and forestal production. Their application 

 is seen at once in questions of drainage, irrigation and fertilising 

 practice. The principal conditions that affect the water loss 

 from plants, together with methods and apparatus for their 

 quantitative estimation, have occupied Livingston and his 

 co-workers, and their results during the last few years have been 

 noteworthy. The conditions as they are now defined by them 

 are four : (1) the evaporating power of the air, (2) the intensity 

 of absorbed radiant energy, (3) the internal transpiring power 



