18 



MASS. EXPERIMENT STATION BULLETIN 339 



Height Diameter of 



of plants Number Length of Length Width stalks topped high 



topped of leaves internodes of leaves of leaves 



Strains high per plant Butt Top 



(inches) (inches) (inches) (inches) (inches) (inches) 



I. For 1934 



Common strain 35.9 17.1 2.1 27.8 12.8 1.4 0.8 



142 33.9 19.1 1.8 26.0 12.3 1.3 0.8 



13 38.9 16.9 2.3 28.5 15.0 1.4 0.8 



29 39.0 18.5 2.1 26 5 13.8 1.3 0.8 



II. For 1935 



Common strain 36.7 17.8 2.1 26.7 13.1 1.4 0.8 



142 38.9 20.0 19 25.3 13.0 1.3 0.7 



13 42.6 17.5 2.4 27.8 14.9 1.4 0.6 



29 43 7 19 9 2.2 26.7 13.9 1.4 0.7 



33 40.9 16.8 2.4 27.9 14.9 1.4 0.7 



Additional data on the comparative shape of leaves of these strains of 

 tobacco grown in 1934 and 1935, but not given here on account of their detailed 

 nature, showed the average shape of leaves produced by Strains 13, 29 and 33 

 under similar conditions to be approximately the same. The leaves produced 

 by these strains were wider at mid-length in comparison to their entire length, 

 than were the leaves produced by the common Havana Seed strain and Strain 

 142A3 under similar growing conditions. 



DEPARTMENT OF ANIMAL HUSBANDRY 

 Victor A. Rice in Charge 



The Relative Efficiency for Milk Production of Proteins from Animal 

 and Vegetable Sources. (J. G. Archibald, V. A. Rice, and C. H. Parsons.) 

 Results of the second phase of this project, on the suitability of dried blood as a 

 source of protein for milk production, have been published in Bulletin 334, 

 entitled 'Dried blood as a source of protein for milking cows." 



The Effect of Feeding a Vitamin A Concentrate on Reproduction 

 in Cattle. (J. G. Archibald, V. A. Rice, and C. H. Parsons.) This project 

 has been continued throughout the year and present plans are to bring it to 

 a conclusion at the end of the barn-feeding season in the spring of 1937. A 

 survey of progress made in June of this year led to the following tentative 

 conclusion: the benefit from the vitamin concentrate, if there be any, seems to 

 be reflected in birth weight and growth rate of the young calves rather than in 

 the growth of heifers after they have passed the calf hood stage of their existence 

 or in the reproductive record of either heifers or mature cows. 



The Effect of Complex Mineral and Vitamin Mixtures on Milk Pro- 

 duction, General Health, and Reproductive Efficiency in Dairy Cattle. 



I. (1. Archibald.) This project, organized in April of this year, is being con- 

 ducted cooperatively with the State Department of Mental Diseases, the 

 milking herds at three of the State hospitals being utilized for the work. 



The object is to determine by carefully conducted feeding trials with large 

 numbers of animals whether mixtures of the nature indicated above have any 

 merit fur the purposes for which they are sold. Approximately 190 cows are 



