456 PLANT GROWTH AND PLANT COMMUNITIES 



the properties of the organized whole are more than the summation of 

 the properties of its parts. 



The burden of this paper is therefore as follows: In the current 

 eagerness to know more and more in detail about ever more refined 

 parts of the system, a sense of perspective is needed. This perspective 

 may be obtained through the need to know how all these parts are put 

 together to create a harmonious working machine, in the organism or 

 even in a single cell. Thus the challenge in cell and plant physiology is 

 increasingly concerned with the problems of organization, and it is, 

 therefore, particularly appropriate to dwell upon them now. 



In a measure this is the old problem of form and function, seen at 

 new and lower levels of organization. The role of organization is clearly 

 paramount when those physiological functions that increase free en- 

 ergy are in question; this is especially true of processes which are 

 directly concerned with growth. Here order is created out of disorder, 

 and the entropy change is negatix^e. Perhaps in too much of our current 

 plant physiology investigators have attempted to seek systems and ex- 

 perimental approaches in which the complications of growth and active 

 metabolism may be avoided. Laudable as this may be when making the 

 first descriptions of possible reactions, of existing enzymes, of the 

 nature of metabolites and catalysts, etc., it is a poor way to face the 

 problems of organization. One would hardly study the operation of the 

 internal combustion engine as it lies idle in the repair shop, often as 

 this may occur! As modern techniques disclose proteins and amino 

 acids even in fossils (see Barghoorn, 1957), the dead fragments of the 

 metabolic machine may become increasingly evident even in the 

 plants of long ago. But neither the form nor the dead substance of the 

 fossil can convey much of an impression of how it grew or metabolized 

 in life. 



There comes a point, therefore, at which the living system can be 

 adequately studied only while it is actively in operation, and increas- 

 ingly the test of viability is whether the conditions of the investigation 

 would permit the living system to grow. Therefore, to leave the con- 

 sideration of growth out of our current study of metabolism, and to 

 assume that what appears in the non-growing, fragmented portions of 

 the system will operate in situ in the same fashion, is like "leaving the 

 Prince of Denmark out of Hamlet." Carried to its logical conclusion, 

 the modern doctrine of molecular biology would have botany a branch 

 of chemistry. But however essential one believes the chemical knowl- 

 edge to be, it alone is not enough. The problems of organization begin 

 at the point where the knowledge of individual molecules and their 

 unit reactions ends. Therefore, if this "sermon" needed a text, or this 

 new laboratory building a dedicatory superscription, my own sugges- 

 tion would be, "Consider the lilies of the field, how they grow. . . ." 



