76 BURTON EDWARD LIVINGSTON 



with whom the supposed student comes mostly in contact, his 

 own previous training and present ability and interest, and the 

 future possibilities which he sees in the line of work to be chosen. 

 We do not need to consider here the various view-points held by 

 the present leaders in the science, nor do we need to dwell upon 

 the various sorts of personal interest and scientific and other 

 training with which it is now possible for a student to present him- 

 self at the door of a research laboratory. It will rather be the 

 aim of these paragraphs to attempt a tentative discussion of the 

 innate possibilities which characterize the main groups of problems, 

 from the array of which choice for a first research is likely to be 

 made. 



LINES OF PHYSIOLOGICAL ACTIVITY 



1. The simplest form of plant physiological study, as of other 

 scientific investigation, appears to be the qualitative descrip- 

 tion of occurrences in nature.^ As examples of this kind of in- 

 quiry may be mentioned such discoveries as the exhibiting by 

 the majority of higher plants of responses to light direction and 

 to the force of gravitation, to water supply and to water loss, and 

 to the presence or absence of certain chemicals in the surround- 

 ings. Before the theories of organic evolution became the center 

 of inertia about which the main mass of biological inquiry revolved 

 these qualitative observations made up a large part of the 

 science ; thus a taxonomy without its basis in phylogeny consisted 

 in such facts as this, that under the natural conditions certain 

 plants develop a burning juice and cruciform flowers, while others 

 as persistently produce bilabiate flowers and an aromatic, volatile 

 oil. Fortunately, so much of this foundation in natural fact 

 has already been accomplished by the great botanical pioneers, 

 that it is now unnecessary for anyone to set out primarily upon 

 this line of categorical description. New and "interesting" quali- 

 tative facts about plant phenomena are no longer apt, per se, to 

 attract much attention among physiologists. Nevertheless, no 

 science can advance without continued activity in descriptive 

 lines, and this sort of study makes up a less interesting portion 

 of all contributions to physiological science today, the interest 



