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SCIENCE 



[Vol. LV, No. 1431 



atmosphere is not developed and maintained. 

 4. Finally, a medical school, both by precept 

 and example, must seek to inoculate a sustain- 

 ing philosophy in the souls of its graduates. 

 The philosophy of medicine implies a cheerful 

 acquiescence to the burdens of the day. It 

 inspires the unfortunate and cheers the de- 

 pressed. It teaches how to encourage the hope- 

 less as well as to relieve the suffering. It pro- 

 vides courage and fortitude with which to meet 

 sorrow and disappointment. Lived up to, it 

 insures a geniality of soul and tolerance for 

 the opinions of others. Dishonesty is its most 

 hated foe. Such a philosophy is needed by 

 every successful clinician : it is practical even 

 though idealistic. It does not develop best in 

 the materialistic atmosphere of a pure science 

 not learned and pursued in love. 



Conclusion. — Brief reference has been made 

 to a few of the dangers inherent in some of 

 the very factors that have made contemporary 

 medicine so brilliant. To infer anything short 

 of an attempt to be constructively critical is to 

 misconstrue. It is hoped that every clinical 

 practitioner and teacher will ponder deeply on 

 these and kindred topics, for clinical medicine 

 is destined to come into its own in the near 

 future. This will be hastened if the entire pro- 

 fession takes a more active share in the diree- 

 ■ tion of education and the enforcement of 

 needed reforms. 



Progress and optimism are the natural 

 progeny of health; they wither in the face of 

 disease. Preventive medicine, through dom- 

 ination of the forces of nature and their util- 

 ization in promoting the welfare of mankind, 

 is the ultimate goal of medical science. Through 

 science the facts are discovered, through clinical 

 practitioners their application is effected. The 

 prevention and cure of many diseases to which 

 mankind is heir depends neither upon the 

 acquisition of knowledge through scientific re- 

 search alone, nor its proper application to 

 patients in the limited domain of each prac- 

 titioner. Medicine must have behind it the tre- 

 mendous power of a concordant public opinion. 

 To win this, scientists, teachers and practition- 

 ers must miss no opportunity to become active 

 agents in the proper transmission of all useful 

 knowledge to the public at large'. In no other 

 way can humanity be freed from the pernicious 



influence of quack remedies, cults of false pre- 

 tenses, and a host of kindred delusions which 

 drain the physical and financial and psychic 

 resources of thousands every year. When fads 

 and personal whims are kept constantly sub- 

 servient to the weight of judiciously proved 

 opinion, and if devotion to truth characterizes 

 the daily life of student and physician — a 

 grateful public will generously suppoi't all 

 forms of needed medical investigation. 



Sydney K. Miller 



PHOTOPERIODISM, THE RESPONSE 

 OF THE PLANT TO RELATIVE 

 LENGTH OF DAY AND NIGHT^ 



In an article published in 1920- data were 

 presented tending to show that the length of 

 day may exercise a remarkable regulatory ac- 

 tion in initiating or inhibiting sexual reproduc- 

 tion in plants. In a number of species studied 

 it was found that ordinarily the plant can 

 attain the flowering and fruiting stage only 

 when the length of day falls within certain 

 limits so that in such cases flowering and fruit- 

 ing occur only at certain seasons of the year. 

 In this respect some species and varieties 

 respond to long days while others respond to 

 short days. Moreover, some plants are much 

 more sensitive to change in length of day than 

 are others. Since the publication of this paper 

 the investigations have been extended to cover 

 various other features of plant activity as af- 

 fected by the prevailing length of day, includ- 

 ing increase in stature, aerial and subterranean 

 branching, formation of tubers and bulbs, root- 

 growth, leaf-fall, dormancy and rejuvenescence. 

 In collaboration with C. W. BacxDn of this office 

 fairly extensive biochemical studies of the sub- 

 ject have been carried out to ascertain the 

 nature of the internal chemical changes involved 

 and their relationship to the observed responses 



1 The writers are indebted to Mr. 0. F. Cook, of 

 the Bureau of Plant Industry, for suggestion of 

 the term pliotoperiodism to designate the phe- 

 nomena in question. 



= ' ' Effect of the Relative Length of Day and 

 Night and Other Factors of the Environment on 

 Growth and Reproduction in Plants," in Journal 

 of Agricultural Eesearch, Vol. 2VIII, No. 11, 

 March 1, 1920, pp. 553-606. 



