343] B. E. Livingston 145 



to the editing of plant physiological papers prepared by work- 

 ers in other institutions, especially for Physiological Re- 

 searches, a series of publications with which the University 

 has no official connection and for which it furnishes no finan- 

 cial assistance. An English translation of Palladia's Plant 

 Physiology, with editorial additions, is about to be pub- 

 lished from this department. It has been prepared from the 

 German translation of the Sixth Eussian edition, with incor- 

 poration of the main alterations occurring in the Seventh 

 Eussian edition. 



Contributions to the Science, and Researches Now in Prog- 

 ress. To give a clear idea of the nature of the investigations 

 attempted in this department, it is desirable to present a 

 brief discussion of the general field in which these investiga- 

 tions lie. The science of plant physiology deals with the pro- 

 cesses or changes that go on in living plants. Now, to un- 

 derstand a change as fully as possible it is required to know 

 the change first in a roughly descriptive sort of way, after 

 which our knowledge is to be advanced by consideration of the 

 dynamic and causal aspects of the process considered. De- 

 scriptive physiology involves statements of the various sorts 

 of processes going on in the organism, and it should show in 

 what regions of the body these changes occur, and when they 

 occur. Thus, that ordinary green leaves take up the element 

 carbon out of the air during periods of sunlight is a state- 

 ment of descriptive physiology, in this sense. To inquire 

 more deeply concerning this process of carbon-intake clearly 

 leads to quantitive studies of the various rates at which this 

 intake may go on, which may be correlated with the various 

 concomitant conditions of the plant and of its surroundings. 

 Such studies soon reveal the fact that the rate of carbon- 

 absorption is determined by a host of conditions, each one of 

 which requires to be measured with regard to its intensity, 

 and it is found that the rate in question may assume different 

 magnitudes as the conditional intensities vary. It is true 

 that the process of carbon-entrance from the air usually 



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