8 



CONTENTS. 



A new method for the approximate mechanical analysis of soils, 

 Tlie 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, .... 



Experiments 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 fertility of cranberry 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 varietifss of corn fodder (entire plant 

 as harvested), ..... 



Composition of different varieties of corn fodder (entire phin 

 dry matt<!r), ...... 



Digestibility of the plant, . . 



Proportions and composition of parts, . 



Condition of crop when cut and character of season 



Average composition of parts, 



Relative proportions of grain and cob, . 



Comjjosition of grain and cob, 



Sununary, ....... 



The digestibility of cattle foods, .... 



Series XII., ...... 



Discussion of the results, .... 



Series XIV., ...... 



Discussion of the results, .... 



Series XV., 



Discussion of the results, .... 



PAOF. 



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