SECRETARY'S REPORT 125 



treated seedlings. The systems that have been studied are the ascorbic 

 acid and polyphenol oxidases involving the copper proteins ; catalase 

 and peroxidase involving the iron proteins ; and various components 

 of the cytochrome enzyme systems. 



Research by Dr. Alice P. Withrow on the effect of plant growth 

 regulators on salt exchange of plants has indicated that high salt-low 

 carbohydrate plants lose salt more rapidly when treated with ammo- 

 nium 2,4-dichlorophenoxyacetate and that low salt-high carbohydrate 

 plants absorb salts less rapidly under the influence of this growth 

 regulator as compared with untreated plants. 



Studies have been initiated on the effect of plant-growth regulators 

 on the respiratory processes in mitochondrial preparations of bean 

 seedlings and rat livers. 



The following research papers by members of the staff have been 

 published during the past year : 



Withrow, R. B., Klein, W. H., Price, L., and Elstad, V. Influence of visible and 



near infrared radiant energy on organ development and pigment synthesis in 



bean and corn. Plant Physiol., vol. 28, pp. 1-14, 1953, 

 Withrow, R, B., and Price, L. Filters for the isolation of narrow regions in 



the visible and near-visible spectrum. Plant Physiol., vol. 28, pp. 105-114, 



1953. 

 Withrow, R. B., and Elstad, V. Water-cooled lamp systems with refluxing 



aqueous filters. Plant Physiol., vol, 28, pp. 334-388, 1953. 

 Withrow, R, B,, and Withrow, Alice P. A linear recording ac conductance 



bridge for measuring salt exchange in plants. Physiol. Plantarum, vol. 6, 



pp. 444-450, 1953. 



Respectfully submitted. 



L. B. Aldrich, Director. 

 Dr. Leonard Carmichael, 



Secretary^ Smithsonian Institution. 



