CONTENTS xi 



CHAPTER XX. 



PROCESSES INFERRED FROM INDIRECT OBSERVATION: GROWTH. 



General Characteristics of the Growth Process 471 



The Influence of Race, Sex and Environment upon the Growth Process . . 484 



The Substrates of Growth '. , . . . . 488 



The Relationship of the Endocrine Organs to Growth . . ..-.. . 493 



The Metabolic Rate and the Partition of Nutrients . . . .' . . . 500 



Catalyzers of Growth . . 503 



Old Age and Senescence 512 



CHAPTER XXI. 



PROCESSES INFERRED FROM INDIRECT OBSERVATION: MEMORY AND SLEEP. 



Memory 521 



The Fatigue Products of Nerve Centers 524 



The Application of the Formula of Autocatalysis to Central Nervous Phe- 

 nomena 527 



Sleep 530 



The Fading of Memory Traces " 532 



PART V. 

 THE PRODUCTS OF TISSUE ACTIVITY. 



CHAPTER XXII. 



THE WASTE PRODUCTS. 



The Carbonaceous Waste Products . . . 537 



The Nitrogenous Waste Products 541 



Conjugated Excreta 554 



Aromatic Oxyacids 558 



Waste Products of the Sulphur Metabolism 559 



Urinary Pigments 562 



The Properties and Composition of Urine 563 



