8 LIST OF ILLUSTRATIONS. 



FIGURE PAGE 



26. Soil bacteria which produce nitrification . . . 103 



27. Soil bacteria which produce tubercles on the roots of 



legumes 108 



28. Diphtheria bacillus 134 



29. Tetanus bacillus * 135 



30. Typhoid bacillus 136 



31. Tuberculosis bacillus 137 



32. Anthrax bacillus 138 



33. White blood corpuscles and other phagocytes . .152 



34. Malarial organism 161 



