CONTENTS. 9 



Department I?ulletin No. 819.— A Pine Yeast Causing Spoilaoe in 



Oysters — -Continued: Page. 



Physical features of the pink yeast 16 



Resistance of the pink yeast to disinfectants 20 



Discussion of results 21 



Summary 23 



Bibliography 24 



Department Bulletin No. 820. — Jack Pine: 



Introduction 1 



Distinguishing characteristics 2 



Range 3 



Forest types 5 



Soil, moisture, and light requirements 6 



Form and development 7 



Reproduction 18 



Susceptibility to injury 20 



Supply of jack pine timber 22 



Characteristics of the wood 22 



Utilization 23 



Stumpage values 27 



Management 28 



Appendix 34 



Department Bulletin No. 821. — Frost Protection in Lemon Orchards: 



Climatic conditions in the Corona district , 1 



Method of orchard heating 3 



Objects of the investigations 5 



Plan of the investigations 7 



Method of securing records 9 



Presentation of data 10 



Lessons taught by the investigations in 1913 22 



The behavior of heated and nonheated plats in 1914 25 



Comparison of the Eureka and Lisbon varieties 27 



Summary 29 



Department Bulletin No. 822. Pears: Production Estimates and 

 Important Commercial Districts and Varieties: 



Relative importance of the pear 1 



Estimated production of pears 1 



Outstanding features of the pear industry 4 



Important commercial districts and varieties, by States 5 



New England States 5 



Middle Atlantic States 6 



East North-Central States 7 



West North-Central States 8 



South Atlantic States 9 



East South-Central States 11 



West South-Central States 11 



Mountain States 13 



Pacific States 14 



Index of States 16 



Department Bulletin No. 823. — Experiments with Kherson and 

 Sixty-day Oats: 



Scope of the investigations 1 



Sources of data 2 



History of the Kherson and Sixty-day oats 2 



Description of Kherson and Sixty-day oats 4 



Experimental data 6 



Varietal experiments in the eastern half of the United States 6 



Varietal experiments in the western half of the United States 36 



Summary of data .■ 66 



General conclusions 68 



Yield of straw, bushel weight, and improvement data 69 



literature cited : 70 



