722 



SCIENCE 



[N. S. Vol. XXXrV. No. 888 



profoundly influence the ideals, the methods 

 and character of academic and professional 

 education. 



The concluding session of the meeting was 

 an informal conference of deans of graduate 

 schools for discussion of questions of policy 

 and administration for mutual enlightenment 

 and better understanding of their common 

 problem, how best to foster the most advanced 

 work done in our universities. Such a con- 

 ference as this had been held at previous meet- 

 ings and had been found to be so necessary 

 that a number of deans of graduate schools 

 were in attendance at their own expense who 

 were not delegates to the association. The 

 questions arising in the administration of 

 graduate schools are so new and important 

 that it is extremely desirable to put the united 

 wisdom and experience of all at the disposal 

 of each, as can be accomplished in no way so 

 well as the free and informal interchange of a 

 round table conference. The meeting as a 

 whole was most useful in bringing together 

 and helping to fuse into a consensus of opinion 

 and action the men controlling the leading 

 universities of the country. 



The annual report to be published later will 

 contain the papers and discussions in full, 

 excepting the conference of deans. 



H. T. Eddy 



SPECIAL ARTICLES 



THE ROLE OF DIFFERENT PROTEINS IN NUTRITION 

 AND GROWTH 



Interest in the study of the problems of 

 nutrition has largely been coincident with the 

 development of the chemical aspects of physi- 

 ology, in distinction from the physical and 

 mechanical phenomena which earlier attracted 

 the attention of investigators. The subject 

 of nutrition has, in large measure, been con- 

 sidered in the past from what might be desig- 

 nated as a statistical standpoint. The balance 

 of income and outgo of energy and matter, 

 nutritive needs and dietary standards, and the 

 effect of external factors on these, are illustra- 

 tions of the type of questions which has called 

 for discussion. With the progress in the study 



of physiological chemistry have come impor- 

 tant additions to our knowledge of the make- 

 up of the foodstuffs and of the real signifi- 

 cance of the processes which take place in the 

 alimentary tract. The conception of digestion 

 as a simple act of solution has evolved into 

 that of an intricate and carefully regulated 

 chemical transformation. The intermediary 

 changes which characterize the metabolism of 

 food materials after absorption and incident 

 to the real nutritive reactions of the body 

 within its tissue cells have at length become 

 the subject of experimental inquiry. 



With this development has come about an 

 appreciation of the specific role of foodstuffs. 

 Various incidents have favored this trend of 

 physiology. The study of enzymes and their 

 striking specificity has served to emphasize the 

 necessity of digestion before the nutrients can 

 satisfy their purposes. Observations on the 

 unique responses of various parts of the ali- 

 mentary tract to different kinds of chemical 

 compounds have brought to light the remark- 

 able interrelations of the secretory and motor 

 functions of the digestive tract and their de- 

 pendence on special (chemical) stimulants. 

 But more important than all this, perhaps, 

 have been the disclosures of the past decade in 

 respect to the chemical structure of the so- 

 called proximate principles, and the proteins 

 in particular. The development of this field 

 of study has been little short of epoch making, 

 so that it seems timely to begin to apply some 

 of the newer knowledge to the investigation of 

 problems in nutrition. 



The idea that proteins of different origin 

 may possess an unlike physiological value is 

 not entirely new. Gelatin, for example, has 

 long been pointed out as an illustration of an 

 inadequate protein. It has been impossible 

 experimentally to sustain life with a diet in 

 which gelatin formed the sole source of nitro- 

 genous intake. To-day one can cite other 

 illustrations of proteins, e. g., zein, gliadin, 

 hordein, casein, which lack some of the char- 

 acteristic amino-acid complexes readily ob- 

 tainable from other albuminous materials 

 which are vaguely regarded as " complete." 

 In still other cases, e. g., edestin and glutenin. 



