ILLUSTRATIONS.

FIGURE.PAGE.
1.Photographs of morning and evening positions of the ‘Praying Palm’[7]
2.The Recording Apparatus[9]
3.Record of diurnal movement of the ‘Praying Palm’[11]
4.  "     "      "  Sijbaria Palm[12]
5.Curve of variation of moto-ex­cit­abil­ity in Mimosa pudica[17]
6.Effect of physio­logic­al depression on diurnal movement of Arenga saccharifera[19]
7.Record of diurnal movements of young procumbent stem of Mimosa pudica[26]
8.Erectile response of Basella to gradual fall of temperature[28]
9.Responsive fall of Basella to gradual rise of temperature"
10.Response of a straight tendril of Passiflora[33]
11.Response of a hooked tendril of Passiflora[35]
12.Response of pulvinus of Mimosa pudica[36]
13.  "     "   Mimosa to variations of turgor[40]
14.Diagram of complete apparatus for record of diurnal variation[46]
15.The Oscillator[50]
16.Effect of cloud on ex­cit­abil­ity of Mimosa[52]
17.Effect of sudden darkness[53]
18.Effect of change from darkness to light[54]
19.Effect of enhanced turgor[55]
20.Effect of moderate cooling[56]
21.Effect of application of intense cold[58]
22.Effect of temperature above the optimum[58]
23.Twenty-four hours’ record of ex­cit­abil­ity of Mimosa[59]
24.Midday record from noon to 3 P.M.[62]
25.Evening record from 6 to 10 P.M.[63]
26.Morning record from 8 A.M. to 12 noon[64]
27.Diurnal variation of ex­cit­abil­ity showing marked nyctitropic movement[65]
28.Diurnal curves of temperature and of corresponding variation of ex­cit­abil­ity of Mimosa[68]
29.Diurnal variation of ex­cit­abil­ity of a summer specimen[70]
30.The Resonant Recorder[76]
31.Variation of ex­cit­abil­ity after section[80]
32.Effect of amputation of upper half of pulvinus of Mimosa[84]
33.Response of Mimosa after amputation of lower half of pulvinus[86]
34.Effect of weight on rapidity of fall[87]
35.Stimulating action of Hydrogen peroxide[88]
36.Incomplete recovery under the action of BaCl2 and transient restoration under tetanisation[89]
37.Antagonistic action of alkali and acid[90]
38.Fatigue due to shortening of recovery-period[91]
39.Effect of constant current in removal of fatigue[92]
40.Stimulating action of light and depressing action of darkness[94]
41.Action of glycerine in enhancing speed and intensity of transmitted excitation in Mimosa[102]
42.Effect of injury in depressing conductivity in normal specimen[104]
43.Effect of injury in enhancing conductivity in a subtonic specimen[105]
44.Diagram of experimental arrangement for conductivity control in Averrhoa bilimbi[109]
45.Diagram of complete experimental arrangement for conductivity control in Mimosa pudica[116]
46.Record showing enhanced velocity in ‘up-hill’ and retarded velocity in ‘down-hill’ trans­mission[121]
47.Direct and after-effect of hetero­dromous and homo­dromous currents[124]
48.Diagram of experimental arrangement for variation of conductivity of animal nerve[126]
49.Effect of hetero­dromous and homo­dromous current in inducing variation of conductivity in nerve[127]
50.Record of ineffectively transmitted salt-tetanus becoming effective under hetero­dromous current[129]
51.Direct and after-effect of homo­dromous current[131]
52.Effect of indirect electric stimulus on the responding leaflet of Averrhoa[136]
53.Staircase responses of sub-tonic specimen of Mimosa to electric shock[145]
54.Staircase responses of sub-tonic specimen of Mimosa to light[147]
55.Positive, diphasic, and negative responses of extremely sub-tonic specimen of Mimosa to successive light stimuli[147]
56.The compound Lever[154]
57.The crank arrangement for oscillation[156]
58.Photograph of the High Magnification Crescograph[157]
59.Crescographic record of absolute rate of growth of Kysoor, and of effects of cold and warmth on stationary and moving plates[161]
60.Record of physical change[164]
61.Records of latent period and time relations of growth response[165]
62.Record of a single growth-pulse of Zephyranthes[167]
63.Records of growth-rate at different temperatures[175]
64.Continuous record of growth, showing temperature minimum[178]
65.Continuous record of growth, showing temperature maximum"
66.The Thermo-Crescent Curve[180]
67.Curve showing the relation between growth and temperature[181]
68.Effects of H2O2, NH3, and ether on growth[184]
69.Effect of CO2 on growth[185]
70.Effect of irrigation on growth[189]
71.Effect of plasmolysis on growth[191]
72.Effect of increasing intensity of electric stimulus on growth[196]
73.Effect of continuous electric stimulation on growth[197]
74.Immediate and after-effects of friction, and of wound on growth[200]
75.Normal retarding effect of light on growth[206]
76.Record showing latent period of growth in response to light[207]
77.Effect of light of increasing intensities[208]
78.Continuous effect of light and of electric stimulus on growth[209]
79.Effects of different rays of the spectrum on growth[210]
80.Photographic records of positive, diphasic and negative electric responses of petiole of Musa[214]
81.Record of growth variation of Crinum under Direct and Indirect stimulus[216]
82.Effect of electric stimulus on sub-tonic specimen of wheat seedling[221]
83.Acceleration of growth under sub-minimal stimulus of light[224]
84.Revival by stimulus of light of autonomous pulsations of Desmodium gyrans at stand still[228]
85.Renewal of growth in the mature style of a flower by the action of stimulus[229]
86.Effect of light in diminution of amplitude and reduction of diastolic limit of pulsation of Desmodium[236]
87.Antagonistic effect of warmth in reduction of systolic limit[237]
88.Contractile response of a growing bud of Crinum[241]
89.Response of Mimosa pulvinus to white light[245]
90.Response of Mimosa pulvinus to blue light[246]
91.Response of Mimosa pulvinus to ultra-violet rays[247]
92.Response of Mimosa pulvinus to thermal radiation[248]

PART I.
RESPONSE OF PLANT ORGANS.