CONTENTS xxi 



PART VI.— GROWTH 

 CHAPTER XXXI 



THE RECORD OF GROWTH-RESPONSE 



PAGE 



The simple Crescograph — The Balanced Crescograph — Rhythmic growth- 

 response — Growth -response and excitatory response — Law of direct and 

 indirect effects of excitation — Positive turgidity-variation as indirect effect 

 of excitation — Mechanical test — Significance of ' inner stimuli ' . . 409 



CHAPTER XXXII 



THE EFFECTS ON GROWTH OF INTERNAL ENERGY 

 AND EXTERNAL STIMULUS 



Characteristics common to growth and to other forms of rhythmic response : 

 (1) Periodic groupings— (2) Effect of external stimulus in renewal of 

 growth when at temporary standstill — (3) Renewal of growth-pulsation 

 by positive turgidity-variation — (4) Effect of increased internal hydro- 

 static pressure— (5) Effect of ascent of sap on growth — Effect of tempera- 

 ture on growth — Comparison of various types of multiple response — 

 Effect of external tension on growth — Effect of direct application of 

 stimulus on the growing region — Similarities between motile and growth 

 responses — Direct and indirect effects of stimulus, and laws of growth . 424 



CHAPTER XXXIII 



ON THE RELATION BETWEEN TEMPERATURE AND GROWTH, 

 AND THE ACCURATE DETERMINATION OF OPTIMUM AND 

 MAXIMUM POINTS 





General consideration of difficulties of accurate determination of effects of 

 temperature on growth — Four accurate methods : (1) Method of discon- 

 tinuous observations— Accurate regulation of temperature by electrolytic 

 rheostat — (2) Method of continuous observations — Thermo-crescent 

 curve — Determination of the optimum point — (3) Method of balance — 

 (4) Method of excitatory response — Translocation of the optimum point 441 



CHAPTER XXXIV 



ON AN ATTEMPT TO DETECT AND MEASURE LATENT STIMULUS," 

 AND ON THE STUDY OF PERIODIC AFTER-EFFECTS 



Positive and negative after-effects — Extreme delicacy of the Method of 

 Balance — Detection of absorbed stimulus by negative after-effect — 



