8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I07 



1934. Some factors influencing the germination of lettuce seed in seed 



laboratory practice. New York State Agr. Exp. Stat., Techn. 

 Bull. 222, 21 pp. 



1935. The formation of a growth inhibiting substance in germinating lettuce 



seeds. Proc. Intern. Seed Testing Assoc, vol. 7, pp. 9-14. 

 Stout, M., and Tolman, B. 



1941. Factors affecting the germination of sugarbeet and other seeds, with 

 special reference to the toxic effects of ammonia. Journ. Agr. Res., 

 vol. 63, pp. 687-713. 

 Thompson, R. C. 



1938. Dormancy in lettuce seed and some factors influencing its germina- 

 tion. U. S. Dep. Agr. Techn. Bull. No. 655, 20 pp. 



