April 14, 1922] 



SCIENCE 



385 



science based on laws or principles of universal 

 applicability. The term "applied science" 

 would seem to connote that these laws or 

 principles are ascertained first and that they 

 are then applied to specific conditions, but as 

 a rule the applications are known and are 

 practiced, having- been hit upon by empirical 

 means and the fii'st function of an applied 

 science is usually to "explain" them by dis- 

 covering the principles involved. When a 

 considerable number of principles have be- 

 come established in this way, new applications 

 for them are found and the applied science 

 becomes in effect what its name implies. 



A large part of the experimental work in 

 horticulture has been conducted with the object 

 of devising new rules and of ascertaining new 

 facts of an empirical nature. More recently, 

 however, considerable effort has been made to 

 find principles of more or less universal ap- 

 plicability and this has been accomplished by 

 a study of the fundamental factors determining 

 plant gi'owth and productivity. Though many 

 valuable practices have not yet received 

 scientific elucidation and though much good 

 work remains to be done in the way of discov- 

 ering new rules, a large body of well estab- 

 lished principles has been accumulated and 

 successful practice depends to an ever increas- 

 ing degree on their recognition. 



A comprehensive investigation of almost any 

 horticultural problem involves much the same 

 succession of stages as has been outlined for 

 the development of the science; (1) The field 

 for investigation is usually explored by ex- 

 perimental work of an empirical natui'e. (2) 

 This is followed by scientific study to determine 

 laws or principles. (3) This in turn is fol- 

 lowed by more experimentation to test the 

 feasibility of applying to particular conditions 

 the principles that have been discovered. It 

 seems customary to extol the scientific study 

 which aims to formulate laws and to dignify it 

 by some such appellation as "fundamental re- 

 search." By implication, the attendant phases 

 of investigation seem to be deprecated on the 

 groimd that they are largely empirical. How- 

 ever, this invidious distinction is unwarranted, 

 as every investigator learns sooner or later, for 



these three aspects of investigation are like 

 three links in a chain and progress in horti- 

 culture depends on their parallel development. 

 Principles are of little value to the horticultur- 

 ist if they cannot be applied, just as a collec- 

 tion of experimental data is of small import 

 until it receives interpretation. 



The strictly scientific aspect of horticulture 

 is closely allied to botany and it is difficult to 

 state wherein the distinction between the two 

 lies. It is largely a difference in emphasis, 

 since the horticulturist is interested onlj' in 

 those phases of botany that may be applied to 

 his specific purposes. Nevertheless, the de- 

 velopment of horticulture has followed closely 

 in the steps of botany. During the last century 

 the attention of most botanists was directed to 

 morphology and taxonomy, a tendency reflected 

 in the advances made by horticulturists in the 

 subject of pollination and fruit setting and in 

 the development and description of varieties. 

 At present these subjects are better rounded 

 and more nearly complete in their major as- 

 pects than almost any other phase of horticul- 

 ture. Now that plant j)liysiology is in ascen- 

 dency, more rapid progress is seen in the nu- 

 tritional problems of horticulture — in fruit 

 bud differentiation, in pruning and in fertilizer 

 treatments. 



The dejjendence of horticultural science not 

 only on botany but on other sciences as well 

 may be illustrated by reference to recent work 

 on the so-called Hardiness Problem. Although 

 this has engaged the attention of both horticul- 

 turists and botanists for many years, until 

 lately little was accomplished other than a sub- 

 stantial verification of the Laws of Tempera- 

 ture formulated by De Candolle nearly a cen- 

 tury ago. Investigators were still faced with 

 the seemingly contradictory facts that death 

 fi'om low temperature is due to loss of water 

 from the cells by ice formation in the intercel- 

 lular spaces and that nevertheless hardy plants 

 usually contain less water than tender plants. 

 What seems to be a satisfactory solution of 

 this problem was made possible by some 

 chemical investigations of Foote and Saxton 

 at Yale University. This work showed that 

 water may exist in dilt'erent forms, and that 



