CONTENTS. 



Department Bulletin No. 285. — The Northern Hardwood Forest: Its 

 Composition, Growth, and Management: Page- 

 Introduction 1 



The northern hardwood forest 2 



Economic importance 27 



Management 33 



Species mentioned in this bulletin 45 



Appendix 47 



Department Bulletin No. 286. — Strength Tests of Structural Timbers 

 Treated by Commercial Wood-preserving Processes: 



Object of the tests 1 



Material tested 2 



Methods of treatment 3 



Method of testing 4 



Results of tests 6 



Deductions 14 



Publications relating to strength tests of various woods 15 



Department Bulletin No. 287. — A Device for Sampling Grain Seeds, and 

 Other Material: 



Introduction 1 



Description of the sampling device , 1 



Operation of the sampling device 3 



Department Bulletin No. 288. — Custom Ginning as a Factor in Cotton- 

 seed Deterioration: 



Introduction 1 



The possibility of mixing seed 2 



Mixing seed in the roll box 3 



Other sources of mixture 6 



Significance of the results obtained 7 



Ways of minimizing the amount of mixing 7 



Department Bulletin No. 289. — Red-clover Seed Production: 



Introduction 1 



Previous investigations on the pollination of red clover 2 



Outline of pollinating experiments 5 



Structure of the red-clover flower 5 



Length of the corolla tube of red-clover flowers 7 



Development of the flowers of red clover 7 



Fertilization of red-clover flowers 10 



Potency of pollen in self-pollination 10 



Cross-pollination and self-pollination of red clover 11 



Artificial manipulation of clover heads 12 



Bumblebees as cross-pollinators of red clover 17 



Honeybees as cross-pollinators of red clover 18 



Mechanical cross-pollinators of red clover 20 



Summary 26 



Department Bulletin No. 290. — Rail Shipments and Distribution of 

 Fresh Tomatoes, 1914: 



Introduction 1 



Methods of cultivation and shipping 2 



Methods used in compiling data 2 



Detailed report of shipments 3 



Shipments by boat 3 



Local shipments :: 4 



Explanation of map 4 



Tomatoes for canning 4 



Commercial supply of table tomatoes 5 



Difficulties encountered 7 



Tomato shipments, 1914 7 



Department Bulletin No. 291. — Breeding Millet and Sorgo for Drought 

 Adaptation : 



Introduction 1 



The place of millet and sorgo in the agriculture of the Great Plains 1 



Adaptations to drought in millet and sorgo 2 



Climatic conditions 3 



Breeding millet for adaptation to drought 4 



Breeding sorgo for adaptation to drought 8 



