LIST OF PUBLICATIONS. 



[Vol. 41 



U. 8. Department of Agriculture — Con. V. 8. Department of Agriculture — Con. 



Weather Bureau : Page. 



Mo.Weather Rev., vol. 47, Nos. 



3-4, Mar.-Apr., 1919___ 417,444 



Cliniat. Data, vol. 0, Nos. 



3-4, Mar.-Apr., 1919 418 



Report 1918 417 



Scientific Contributions : ' 



Ilex vomitoria as a Native 

 Source of Caffeln, F. B. 

 Power and V. K. Chesnut- 409 



The Growth of Certain Bac- 

 teria in Media of Different 

 Hydrogen-Ion Concentra- 

 tions, B. Cohen and W. M. 

 Clark 410 



An Improved Method for the 

 Quantitative Determina- 

 tion of Caffein in Vege- 

 table Material, F. B. 

 Power and V. K. Ches- 

 nut 412 



The Cuprous Chlorid-Iodin 

 Method for Reducing Su- 

 gars Simplltied, F. M. 

 Scales 412 



Pyrolusite from Virginia, T. 

 L. Watson and E. T. 

 Wherry 420 



Merrillla, a New Rutaceous 

 Genus of the Tribe Citreje 

 from the Malay Peninsula, 

 W. T. Swingle 432 



A Reason for the Contra- 

 dictory Results in Corn 

 Experiments, L. Carrier 436 



Structure of the Maize Ear 

 as Indicated in Zea-Euch- 

 Isena Hybrids, G. N. Col- 

 lins 436 



Gigantism in Nocotiana tab- 

 ac~um and Its Alternative 

 Inheritance, H. A. Allard_ 440 



The Mendelian Behavior of 

 Aurea Character in a 

 Cross between Two Va- 

 rieties of Nicotiana rus- 

 tica, H. A. Allard 440 



On the Blooming and Ferti- 

 lization of Wheat Flow- 

 ers, C. E. Leighty and T. 

 B. Hutcheson 440 



Protecting American Crop 

 Plants against Alien Ene- 

 mies, B. T. Galloway 443 



Scientific Contributions — Con. Page. 



Standardizing the Hamper, 



F. P. Downing 443 



Berry Boxes and Fruit Bas- 

 kets, F. P. Downing 443 



The Commercial Apple In- 

 dustiy in the United 

 States, J. C. Folger 444 



Avocados, Particularly 

 Guatemalans, W. Po- 

 penoe 446 



Progress in Breeding Free- 

 sias, W. Van Fleet 448 



Plant Pathology Today, C. L. 



Shear and N. E. Stevens_ 450 



Some Necessary Steps in 

 Any Attempt to Prove In- 

 s e c t Transmis.sion o r 

 Causation of Disease, W. 

 D. Pierce 456 



The Fungus Parasite of the 

 Periodical Cicada, A. T. 

 Speare 456 



A Review of the Leaf Hop- 

 pers of the Genus Gypona 

 North of Mexico, E. H. 

 Gibson 456 



A Microlepldopteran Injuri- 

 ous to Avocado, A. Busck_ 460 



Cane Borer Parasite Work 



in 1919, T. E. Holloway__ 462 



Descriptions of Four New 

 Parasitic Hymenoptera, S. 

 A. Rohwer 463 



The Zinc Content of Some 

 Food Products, V. Birck- 

 ner 464 



Zinc in Oysters, R. S. Hilt- 



ner and H. J. Wichmann_ 464 



On the Nature of Size Fac- 

 tors, S. Wright 473 



Factory Butter, Cheese, and 

 Condensed Milk Produc- 

 tion during the War, T. R. 

 Pirtle 473 



Abortion Disease of Cattle, 



W. E. Cotton 479 



Segment Blocks have Ad- 

 vantages on Larger Size 

 Drains, D. L. Yarnell 483 



Progressive Erosion in a 

 Dredged Drainage Chan- 

 nel, C. E. Ramser 483 



* Printed in scientific and technical publications outside the Department. 



