SECTION OP SANITARY AND MEDICAL SCIENCE 



Ward Giltner, Chairman 



A Microscopic Method of Examining Butter for Microorganisms. G. L. A. Ruehle 123 

 The Relation of Bacillus botulinus to Certain Phases of Home Economics and Agri- 

 culture. Zae Northrup ___- — ------— 127 



Studies in the Bacteriology of the Cold Pack Canning Method. Ruth Normington 133 



SECTION OF AGRICULTURE 



F. A. Spragg, Chairman. 



The Origin and Development of Pedigreed Vaileties of Grain. H. S. Osier - - 139 

 Elements of High Fecundity. M. E. Dickson ________ 145 



The Michigan Crop Improvement Association. J. W. Nlcolson - _ - - - 147 



SECTION OP BOTANY 



J. H. Ehlers, Chairman 



The Manufacture of Sugar from Arenga saccharifcra in Asahan on the East Coast of 



Sumatra. H. H. Bartlett ___________ 155 



Michigan — An Important Source of Raw Vegetable Products. Henry Kraemer - 167 

 Farms vs. Forests. P. S. Lovejoy ___________ 20I 



Some Phytogeographic Observations in Lake County, Michigan. LeRoy H. Harvey 213 

 A Study in the Difference in Soil Requirements on Pine and Spnice. L. J. Young - 219 

 The Biological Method of Determining Fertilizer Requirements of a Particular Soil 



or Crop. R. P. Hibbard and S. Gershberg __-___-- 223 

 Correlation of Variation in Resin Content of Podophyllum with Certain Habitats. 



W. R. M. Scott and E. J. Petry __________ 225 



Periodicity of Elongation and Cell Division. Ray C. Friesner _ _ - - - 233 

 On the Occurrence of Root-Hairs on Old Roots of Helianthus rigidus. E. E. 



Watson- _____-_--__--_- 235 



A Collection of Sphagnum from the Douglas Lake Region, Cheboygan County, 



Michigan. W. E. Praeger ___________ 237 



Distribution of the Orchidaceae in Michigan. H. T. Darlington - - - - - 239 



The Heredity of "Rogue" Types in Garden Peas iPisiim sativum). W. E. Brother- 

 ton, Jr ---------------- 263 



Observations on the Potato Disease Conditions in Michigan for the Summer of 1918. 



E. F. Woodcock -__--__--___-- 281 

 Gtiide to the Literature for the Identification of Fungi. E. A. Bessey - _ _ _ 287 

 The Effect of Parasitism upon the Parasite: A Study in Phylogeny. E. A. Bessey - 317 

 Formaldehyde Injury to Wheat. G. H. Coons and H. H. McKinney - - - 321 



Phenol Injury to Apples. G. H. Coohs and G. Gillette - - - - - -325 



Michigan Plant Disease Survey for 1918. G. H. Coons - - - - - -331 



Notes on Michigan Flora II. O. A. Farwell _--______ 345 



Meteorological Data. Douglas Lake, Michigan, 1912-1918. Prank C. Gates and 



Ruth E. Hurd -________-__-- 373 



