Malformations, 211
  heredity of, 215

Maternal impressions, 212

Nervous system, 228
  disease of, 230
  effect of social life on, 233

Neurasthenia, 238

Old age, 51
  atrophy in, 51
  blood vessels in, 54
  causes of death in, 56
  in animals and plants, 55
  mental activity in, 53

Osmosis, 91

Opsonius, 153

Ovum, 201
  fertilization of, 198
  infection of, 199

Phagocytosis, 86

Plague, 182
  transmission by animals, 183

Plasmodium Malariae, 175

Preventive medicine, 242

Protozoa, 124
  distribution in nature, 125
  mode of growth, 125
  sexual differentiation, 125
  spore formation, 125

Polyomyelitis, 190

Repair, 46 conditions influencing, 47

Scar, 49

Skin, 21

Sleeping sickness, 173

Smallpox, 187

Spontaneous generation, 106

Sunburn, 83

Syphilis, 193

Tetanus, 142

Thymus, 52

Thyroid, 37

Tonsils, 52

Toxins, 144

Tropisms, 93

Trypanosomes, 172

Tuberculosis, 163 infection by sputum, 169 modes of extension, 163

Tumors, 64
  benign and malignant, 69
  cells of, 66
  color, size and shape, 65
  growth of, 65
  importance of, 77
  origin of, 66
  question of increase, 69
  theories of cause, 71
  treatment of, 77

Typhoid fever, 170

Ultra-microscopic organisms, 128

Virus, 128

Yellow fever, 178