ANNUAL REPORT, 1937 41 



Physical and Chemical Properties of Mosaic Viruses. (Monroe E. Freeman.) 

 Eleven specimens of virus-infected tomato plants collected in commercial green- 

 houses in Massachusetts were examined. Ordinary tobacco mosaic virus was 

 the only agent identified. Although abnormal symptoms were noted in some test 

 plants, other agents were not found. 



Connecticut Broadleaf tobacco seedlings were found to be the most successful 

 test plants for the potato vein banding virus. Other varieties and strains of 

 tobacco developed the typical symptoms more slowly and in many cases the 

 symptoms were not distinct. No test plants could be found for this virus that 

 would produce local lesions suitable for semi-quantitative assay. Plant juices 

 containing this virus clarified by freezing, filtering, or low^-speed centrifuging 

 lost to a large extent their ability to infect tobacco seedlings. The evidence 

 seems to suggest that most of the virus is associated with the chloroplasts or the 

 heavier particles of the cellular debris. Experiments on this phase and on the 

 eflfect of \'arious chemical reagents are in progress. 



The Effect of Storage and Processing on the Carbohydrates of Some Varieties 

 of Edible Onions. (Emmett Bennett.) The project was created for the purpose 

 of characterizing the carbohydrates of the onion and ascertaining the changes 

 in this group which have been effected by prevailing storage conditions and 

 by cooking. 



Samples of U. S. No. 1 onions, grown from both seed and sets under similar 

 conditions, were obtained from the Frank D. Hubbard Farms, Sunderland, 

 Massachusetts. Representative samples of both types have been stored under 

 varied conditions. To date, December 16, 1937, practical!}- all of the onions grown 

 from seed have sprouted regardless of storage conditions. Raw and cooked onions 

 of both types have been prepared for analysis. Analytical data will not be avail- 

 able until after the storage period. 



Lignin and Its Relation to the Absorption of Minerals by Plants. (Emmett 

 Bennett.) This project is intended to reveal more of the chemical nature of 

 lignin and to ascertain to a better degree the functions, if any, of the lignin in the 

 soil with respect to plant nutrition. Lignin for this purpose has been isolated 

 from corn cob and purified. Data are not yet available because of the short 

 time this project has been in progress. 



The Nutritive Value of Rare Elements in Plant Nutrition. The Comparative 

 Nutritive Effects of Copper, Zinc, Chromium, and Molybdenum. (H. R. DeRose, 

 W. S. Eisenmenger, and W. S. Ritchie.) The report of work on this project is 

 given in the report of the Department of Agronomy. 



Changes in Frozen Meat During Storage. (W. S. Ritchie.) This project had 

 for its objective the determination of the changes, chemical and physical, occur- 

 ring in meat during storage at freezing temperatures. 



Samples for the work now in progress originated at Purdue University as the 

 result of a feeding trial with hogs. The hogs were slaughtered and processed by 

 Kingan and Company of Indianapolis and frozen by the Birds Eye Frosted Foods 

 Corporation of Boston. Samples were furnished immediately on the killing of 

 the hogs and again after freezing for a week or ten days. Subsequent samples 

 from the same group of animals will appear at intervals of three, six, nine and 

 twelve months. The work in progress includes the determination of the vitamin 

 B and G content of the meat, the biological and growth-promoting value of its 

 protein, tenderness, and nitrogen fractions as well as the usual analysis for total 

 protein, fat, ash, and water. 



