Xll 



CONTENTS 



PAGE 



87. Glucosides, tannin, and phenols 491 



88. Pigments 494 



89. Alkaloids, ptomaines, and other poisons 498 



90. Ethereal oils, resins, &c 500 



91. Enzymes 501 



92. External influences 510 



93. Self-regulation 514 



CHAPTER IX 

 RESPIRATION AND FERMENTATION 



94. Introductory . . . . . . . . . . . . .518 



95. Aerobic respiration 519 



96. Products of aerobic respiration 526 



