CONTENTS. V 



Report of the Chief of the Bureau of Plant Industry — Continued. Page. 



Vegetables . 273 



Forest diseases 277 



Plant nutrition 279 



Sources of crude rubber 282 



Explorations and plant introductions 284 



Ornamental plants 286 



Seed investigations 287 



Congressional seed distribution 288 



Report of the Forester 289 



National forest policy 289 



Forestry in Alaska 293 



The personnel of the Forest Service 294 



National forest receipts and expenditures 298 



The National forest properties 300 



Forest protection 304 



National forest management 313 



Research 333 



Informational and educational activities 343 



Report of the Chemist 345 



Introduction 345 



Agricultural chemical investigations 345 



Color, medicinal, and technical investigations 359 



Work for other departments 360 



Enforcement of regulatory laws 361 



Report of the Chief of the Bureau of Soils 373 



Soil survey 373 



Chemical Division 376 



Soil physics 377 



Fertilizer resources 378 



Report of the Entomologist 381 



Deciduous fruit insect investigations 381 



Work on the gipsy moth and the brown-tail moth 388 



Cereal and forage insect investigations 392 



Stored-product insect investigations 395 



Tropical and subtropical fruit insects 397 



Vegetable and truck-crop insect investigations 400 



Southern field-crop insect investigations 404 



Insects affecting the health of man and domestic animals 408 



Insects affecting forest resources and shade trees 410 



Bee-culture investigations 412 



Insect pest survey 417 



Report of Chief of Bureau of Biological Survey 419 



Organization of the bureau 419 



Economic investigations 420 



Food habits research 437 



Biological investigations 440 



Alaska investigations 446 



Game and bird refuges _-_ 450 



Migratory-bird treaty and Lacey Acts 455 



Publications issued from the bureau during the year 461 



Report of the Chief of the Bureau of Public Roads 463 



Introduction 463 



Federal aid road work 464 



Designation of the Federal-aid highway system 464 



Road construction in the National forests 465 



Investigations in highway economics : 466 



Important observations from the Connecticut transportation survey. 468 



Study methods of highway finance 468 



Motor-truck transportation in New England 469 



The influence of highway improvement on rural land values 470 



Physical researches and tests 470 



Farm drainage investigations 476 



Farm irrigation investigations 480 



Farm engineering investigations 485 



Distribution of surplus war materials 489 



Extension activities - 493 



