42 MASS. EXPERIMENT STATION BULLETIN 398 



Packet Seed Studies. (Clark L. Thayer.) The Department of Floriculture 

 cooperated with the Seed Laboratory for the seventh season in conducting tests 

 to determine the quality of flower seeds sold in retail seed stores, chain stores, 

 schools, and other outlets. The seeds were tested for germination and performance 

 under field conditions. Results are reported in Control Series Bulletin 115. 



DEPARTMENT OF HOME ECONOMICS NUTRITION 

 Julia O. Holmes in Charge 



Vitamin Requirements of Older People. (A. \V. Wertz.) The urinary thiamin 

 excretion of three elderlj' women was followed for a period of 14 weeks. The 

 diet was supplemented with 3 mg. of thiamin chloride for the first half of the 

 period and then with 1 mg. thiamin plus enough yeast to bnng the total thiamin 

 to 3 mg. The excretion of thiamin in the urine was almost twice as much in the 

 latter period as in the first period, although the intake of thiamin was identical. 

 This might indicate that there is some factor supplied by the yeast which has a 

 definite effect on thiamin utilization in the body. There was no change in the 

 electrocardiograms from the first period. The hemoglobin values decreased. 



The Effect of Temperature on Calcium Metabolism in Growing Rats. (Marie 

 S. Gutowska.) One series of experiments was conducted at temperatjures below 

 57° and above 9C°F. (approximately the limits beyond which the albino rat will 

 not breed satisfactorily); and another series at 73° and 83° (corresponding to the 

 normal range of breeding temperatures). In both series the calcium retention 

 was greater in the low-temperature group, whether determined by balance experi- 

 ments or by carcass analysis. Growth was slower at the low temperatures. 

 Food consumption was considerably larger in the groups of slow-growing rats 

 kept at the lower temperatures, but food utilization was noticeably lower than in 

 the groups kept at the higher temperatures. It was concluded that temperature 

 plays a much greater role in practical nutrition than is now realized. 



It is hoped that these findings, if confirmed by tests on adult rats now in prog- 

 ress, may have some bearing on the food requirements of humans as influenced 

 by varying ranges in temperature. 



The Effect of Temperature on the Cure of Rickets. (Marie S. Gutowska.) 

 Two groups of six rats each were depleted of their vitamm D and placed in closed 

 cabinets, one group at 66°F., the other at 82°. All received in three days 4 U.S. P. 

 units of vitamin D. Two rats from each group were killed on the fourth, sixth, 

 and eighth day from the beginnmg of the assay period. It was apparent, both 

 from photographs and from line tests, that the rats kept at the lower temperature 

 showed an earlier response to the treatment and an earlier healing of the rachitic 

 sections than the rats kept at the higher temperature. It was concluded that the 

 biological materials and the temperature at which the bioa.ssay is conducted must 

 be standardized in order to reduce the errors of the test; and that by lowering the 

 temperature, it may be possible to shorten the time of the assay. 



Manganese Balance Experiments with Birds. (Marie S. Gutowska with the 

 cooperation of J. W. Kuzmeski of the Feed Control Service.) Manganese metab- 

 olism studies were conducted in two series of experiments. The first series was 

 conducted with two groups of laying hens fed for a period of three months on 

 rations varying only in mangenese content (76 p. p.m. and 21 p. p.m.). The drop- 

 pings were collected every three hours during a period of a week and five periods 

 of a week each formed the series. The second series consisted of the same number 



