CONTENTS. 



A new method for tho approximate mechanical anal5^=;is of soils, 

 The present status of soil sterilization, ..... 

 Influence of soil decoctions from sterilized and unsterilized soils 

 upon bacterial growth, .... 



Protozoa as a factor in the bacterial flora of soils, 



Conclusions, ...... 



The effects of positive and negative electrical charges on seeds and 

 seedlings, ...... 



Electrical resistance of trees, .... 



Exi)eriments with cut branches of trees, 



Experiments with small plants, 



Relation of electrical resistance to flow of sap, 



Electrical resistance of different tissues, 



Relationship of electrical resistance to other factors 



Influence of temperature on resistance, . 



Conclusions, ...... 



The chemistry of arsenical insecticides, 



General introduction, ..... 



Paris green, ...... 



Calcium arsenite, ..... 



Lead arsenates, ...... 



The natural fertilit}'^ of cran])erry bogs. 

 Types of corn suited to Massachusetts, 



Soil, cultivation, size of plots, fertilizers used, 



Description of varieties, .... 



Yield per acre of entire corn plant. 



Effect of season on yield, .... 



Composition of different varieties of corn fodder (entire plant 

 as harvested), 



Composition of different varieties of corn fodder (entire plant 

 dry matter), .... 



Digestil)ility of the plant. 



Proportions and composition of parts. 



Condition of crop when cut and character of season 



Average composition of parts. 



Relative jiroportions of grain and cob, 



Composition of grain and cob. 



Summary, . 

 The digestibility of cattle foods, 



Series XII., 



Discussion of the results. 



Series XIV., 



Discussion of the results. 



Series XV., 

 Discussion of the results, 



115 

 121 



