180 FOREST DISTRIBUTION 



ty northwestern South Dakota. Bull. S. D. Geol. Surv. 6 : 1-126. 

 pi. 1-6. Mr 1914. 



69. Ward, Lester F. Status of the mesozoic floras of the 

 United States. Monog. U. S. Geol. Surv. 48 : 1-616. pi. 1-109. 

 1905. 



70. Weather Bureau. Summary of the elimatological data 

 of the United States by sections. 26 : 1-4. f. 1-2. 27 : 1-7. /. 

 1-2. 28 : 1-7. /. 1-2. 39 : 1-7. /. 1-2. 30 : 1-6. f. 1-2. 



71. Weaver, J. E. A study of the vegetation of southeast- 

 ern Washington. Univ. Neb. Studies 17 : 1-114. /. 2-45. Ja 1917. 



72. Weaver, J. B. and Thiel, A. B. Ecological studies in 

 the tension zone between prairie and woodland. Bot. Surv. Neb. 

 NS. I. 1 : 1-57. /. 1-38. Ap 1917. 



73. Whitpord, H. N. The forests of the Flathead Valley. 

 Bot. Gaz. 39 : 99-122. F. 194-218. Mr. 276-296. Ap. f. 1-23. 

 1905. 



74. ZoN, Raphael, and Graves, H. S. Light in relation 

 to tree growth. Bull. For. Serv. U. S. Dept. Agric. 92: 1-59. 

 /. 1-10. Je 1911. 



75. ZoN, Raphael. Seed production of western white pine. 

 Bull. U. S. Dept. Agric. 210: 1-15. Ap 1915. 



