Maech 18, 1898.] 



SCIENCE. 



371 



the protoplasm of plants, and the functions 

 of the organisms into which it is formed. 

 It is, therefore, a study of activities and re- 

 gards structures from the standpoint of 

 efficiency or functional value, and it in- 

 cludes the consideration of all reactions of 

 growth, movement, metabolism, changes in 

 form, irritability and other phenomena re- 

 sulting from the activity of forces internal 

 to the plant whether set in motion by in- 

 ternal or external stimuli. It merges into 

 morphology in the subjects of growth and 

 reproduction upon the one hand, and upon 

 the other it underlies a portion of the do- 

 main of ecology, in the consideration of 

 adaptative reactions, while with bacteri- 

 ology and mycology it forms the basis of 

 the study of pathology. Physiology and 

 chemistry join in the consideration of the 

 chemical activities and products of the 

 organism, and the principles of physics are 

 involved in the investigation of the plant 

 machine. 



It is not possible, nor would it be profit- 

 able, to separate the botanical branches too 

 sharply in instruction or research. Some 

 exposition of the principal functions of 

 plants might well accompany an elementary 

 course in morphology, and it goes without 

 saying that a knowledge of anatomy is 'a 

 prerequisite to the successful comprehension 

 of the physiology of an organism, although 

 some knowledge of the general principles 

 may be obtained without it. Then again, 

 it will often be found most profitable to ex- 

 tend work in physiology to include an in- 

 terpretation of the more prominent adapta- 

 tions, especially those of an ontogenetic 

 character. To attempt to deal with such 

 phases of plant life in instruction or re- 

 search without a comprehension of the 

 physiological principles involved is pure as- 

 sumption. 



In agricultural colleges and experiment 

 stations the botanical problems and courses 

 of foremost importance would be those deal- 



ing with nutrition and plant diseases. In 

 this instance the work of the physiologist 

 might well extend to cover almost all of the 

 field of the pathologist. 



The opinion that the main principles of 

 physiology have been determined, and that 

 only their minor and incidental application 

 await delineation at the hands of the in- 

 vestigator, has been expressed concerning 

 several subjects so many times in the last 

 century that it needs no further notice at 

 this time. 



A systematic survey reveals the fact that, 

 instead of a complete and thorough plot- 

 ting of the great field of physiology, we 

 have made here and there a few simple 

 trails through the dense jungle of ungrouped 

 and vaguely defined principles, and the 

 greater part of the work is yet to be accom- 

 plished. 



The fundamental problem of the consti- 

 tution of living matter still confronts us. 

 It is quite true that the chemical structure 

 of its chief constituents, the proteids, is not 

 yet determined, but even when this shall 

 be known and the synthesis of this difficult 

 group be accomplished we shall be but a 

 step on the way, for there will still lie ahead 

 of us the unknown physiological characters 

 of the physical basis of life. Indeed, we 

 may not say that we have determined even 

 the limits of the gross anatomical existence 

 of living matter, since there may well be 

 stages of living matter or classes of or- 

 ganisms which so far have eluded our opti- 

 cal apparatus. 



We have not yet succeeded in interpret- 

 ing clearly even the cruder visible phenom- 

 ena of the cell. The causes, character and 

 purposes of cytoplasmic movement, the in- 

 ter-relation of the organs of the cell, the 

 nature of the activity of the plastids, the 

 functional value of the nuclear constituents, 

 and the operative relation of the protoplast 

 to its membrane, are still open questions, 

 while nothing but the crudest diagram of 



