Comparative Electro-Physiology: A Physico-Physiological Study

Observations of Burdon Sanderson on leaf-response in Déone@a—Leaf and stalk currents—Their opposite variations under stimulus—Similar leaf- and-stalk currents shown to exist in ordinary leaf of Ficus religiosa— Opposite-directioned currents in Cztrus decumana—True explanation of these resting-currents and their variations—Electrical effect of section of petiole on Dzonea and Ficus religiosa—Fundamental experiment of Burdon Sanderson on lamina of Dzone@a— Subsequent results—Expeti- mental arrangement with symmetrical contacts—Parallel experiments on > sheathing leaf of /usa—Explanation of various results : ‘ 1223

Electrical organs in fishes—Typical instances, Zorpedo and Malepterurus— Vegetal analogues, leaf of Pterospermum and carpel of D¢llenia indica or pitcher of Mefenthe—Electrical response to transmitted excitation —Response to direct excitation—Uni-directioned response to homo- - dromous and heterodromous shocks—Definite-directioned response shown to be due to differential excitability—Response to equi-alternating electrical shocks—Rheotomic observations—Multiple excitations— Multiplication of terminal electromotive effect, by pile-like arrangement, in bulb of Uric/zs lily : ‘ ‘ , ; ‘ , . . 241

Existing theories—Their inadequacy—-The ‘ blaze-current’ so called—Re- sponse uni-directioned, to shocks homodromous or heterodromous, characteristic of electric organs—Similar results with inorganic specimens —Uni-directioned response due to differential excitability— Electrical response of pulvinus of A//mosa to equi-alternating electric shocks—Re- sponse of petiole of AZ#sa—Of plagiotropic stem of Cucurdita—-Of Eel— The organ-current of electric fishes—Multiple responses of electrical organ—Multiple responses of Bzofhyium . — . > : : . 250

Advantage of electrical stimulation, in its flexibility—Drawbacks due to~ fluctuating factors of polar effects, and counter polarisation-current— Difficulties overcome by employment of equi-alternating © electric shocks—Methods of the After-effect and Direct-effect—Experiment of Von Fleischl on response of nerve—Complications arising from use of make and break shocks—Rotating reverser— Motor transformer—Re- sponse of Musa to equi-alternating shocks—Abolition of this response by chloroform—Response records of plagiotropic Cucurbita and Eel— Differential excitability of variegated leaves, demonstrated by electric response. é ita : > ; - ; : : eee

Currents of rest and action—Currents in animal skin—Theories regarding these—Response of vegetal skin—Stimulation by Rotary Mechanical _Stimulator—Response of intact human skin--Isolated responses of upper and. lower surfaces of specimens —Resultant response brought about by differential excitability of the two surfaces—Differences of excitability between two surfaces accounted for—Response of animal and vegetal skins not essentially different—General formula for all types of response of skin—Response of skin to different forms of stimulation gives similar results— Response to equi-alternating electric shocks : (1) Method of the After Effect ; (2) Method of Direct Effect—Response of grape skin—Similar response of frog’s skin—Phasic variation of current of rest induced as result of successive stimulation in (a) grape skin ; (4) frog’s skin; (¢c) pulvinus of Jimosa—Phasic variation in autonomous me- chanical response of Desmodium gyrans—Autonomous variation of current of rest—True current of rest in skin from outer to inner—This may be reversed as an excitatory after-effect of preparation—Electrical response of skin of neck of tortoise—Electrical response of skin of tomato—Normal response and positive after-effect—Response of skin of gecko—Explanation of abnormal response. . ; . . 287

Epidermal, epithelial, and secreting membranes in plant tissues—Natural resting-current from epidermal to epithelial or secretory surfaces —Current of response from epithelial or secretory to epidermal surface:—Response of Dil/enza—Response of water-melon—Response of foot of snail—The so-called current of rest from glandular surface really due to injury— Misinterpretation arising from response by so-called ‘ positive variation ’ —Natural current in intact foot of snail, and its variation on section— Response of intact human armpit—Response of intact human lip— Lingual response in man—Reversal of normal response under sub- minimal or super-maximal stimulation—Differential excitations of two surfaces under different intensities of stimulus, with consequent changes in direction of responsive currents, diagrammatically represented in characteristic curves—Records exhibiting responsive reversals. rita. 3 Se

Consideration of the functional peculiarities of the digestive organ—Alter- nating phases of secretion and absorption—Relation between secretory and contractile responses. [Illustrated by (a) preparation of Mimosa; (4) glandular tentacle of Drvosera—General occurrence of contractile re- sponse—True current of rest in digestive organs—Experiments on the pitcher of Wepenthe—Three definite types of response under different con- ditions—Negative and positive electrical responses, concomitant with secretion and absorption— Multiple responses due to strong stimulation —Response in glandular leaf of Drosera—Normal negative response reversed to positive under continuous stimulation— Multiple response in Drosera—Response of frog’s stomach to mechanical stimulation—Re- sponse of stomach of tortoise—Response of stomach of gecko— Multiple

_ response of frog’s stomach, showing three stages—-negative, diphasic, and positive —Phasic variations : : ; ‘ , 329 Parallelism between responsive reactions of root and digestive organ—Alter- nating phases of secretion and absorption—Association of absorptive process with ascent of sap—Electrical response of young and old roots— Different phasic reactions, as in pitcher of /Vepenthe—Response to chemical stimulation—Different theories of ascent of sap-——Physical versus excitatory theories—Objections to excitatory theory—Assumption that wood dead unjustified—Demonstration of excitatory electrical re- sponse of sap-wood—Strasburger’s experiments on effect of poisons on ascent of sap—Current inference unjustified . : : ‘ ; - 349

Propagation of excitatory wave in plant attended by progressive movement of water—Hydraulic response to stimulus—The Shoshungraph— Direct and photographic methods of record—Responsive variations of suction under physiological modifications induced by various agents—Effects of lower- ing and raising of temperature—Explanation of maintenance of suction, when root killed—Effect of poison influenced by tonic condition—Effect of anzesthetics on suctional response—Excitatory versws osmotic action —Stimulation by alternating induction-shocks—Terminal and sub-ter- minal modes of application—-Three modes of obtaining response-records, namely (1) the unbalanced, (2) the balanced, (3) the over-balanced— Renewal of suction previously at standstill, by action of stimulus--Re- ponsive enhancement of suction by stimulus—After-effect of stimulus— Diminution of latent period as after-effect of stimulus—Response under over-balance—Response under sub-terminal stimulation—Variation of response under seasonal changes .

Heliotropic plant movements reducible to fundamental reaction of contrac- tion or expansion—Various mechanical effects of light in pulvinated and growing organs—Electrical response induced by light not specific, but concomitant to excitatory effects—Electrical response of plant to light not determined by presence or absence of chloroplasts—Effect of unilateral application of stimulus on transversely distal point— Positive response due to indirect. effect and negative to transmission of true excitation—Mechanical response of leaf of AM/¢mosa to light applied on upper half of pulvinus—Mechanical response consists of erection or positive movement, followed by fall or negative movement—FElectrical response of leaf of A/zmosa to light applied on upper half of pulvinus ; induction in lower half of pulvinus of positivity followed by negativity— Longitudinal transmission of excitatory effect, with concomitant galvano- metric negativity --Direct effect of light and positive after effect— Circumstances which are effective in reversing normal response—Plants in slightly sub-tonic condition give positive followed by negative response —Exemplified by (a) electrical and (4) growth response—Examples of positive response to light—Periodic variation of excitability— Multiple mechanical response under light—Direct and after-effect— Multiple electrical response under light, with phasic alterations of (— + — +) or (+ — + —)--After-effects ; unmasking of antagonistic elements, either plus or minus—Three types of after-effects

Response of retina—Determination of true current of rest—Determination _ of differential excitabilities of optic’ nerve and cornea, and optic nerve and retina—The so-called positive variation of previous observers indicates the true excitatory negative—Retino-motor effects—Motile responses in nerve— Varying responsive effects under different conditions —Reversal of the normal response of light due to (1) depression of excitability below par ; (2) fatigue—The sequence of responsive phases during and after application of light—Demonstration of multiple responses in retina under light, as analogous fo those in vegetable tissues — Three types of after-effect—Multiple after-excitations in human retina—Binocular Alternation of Vision—Demonstration of pulsatory response in human retina during exposure to light —. , ‘ - 415

‘Theory of Hydrostatic Pressure and Theory of Statoliths—Question regarding active factor of curvature in geotropic response, whether contraction or expansion—Crucial experiment by local application of cold—Reasons for delay in initiation of true geotropic response—Geo-electric response of shoot —Due to active contraction of upper side, with concomitant gal-— vanometric negativity—Geo-electric response of an organ physically restrained . ; : ; : . , . : ; ; «5 @34

Transmission of excitation in plants not due to hydromechanical disturbance, but instance of transmission of protoplasmic changes—Difficulties in accurate determination of velocity of transmission—A perfect method— Diminution of conductivity by fatigue—Increased velocity of transmission with increasing stimulus—Effect of cold in diminishing conductivity — Effect of rise of temperature in ‘enhancing conductivity— Excitatory concomitant of mechanical and electrical response—Electrical methods of determining velocity of transmission—Method of comparison of longi- tudinal and transverse conductivities—Tables of comparative velocities in animal and plant —Existence of two distinct nervous impulses, positive and negative ; ; Saas , ° . ; ; ; » 444 «

Drawbacks to use of electrical stimulus in nehenpading electrical response — Response to equi-alternating electrical shocks—Modification of response by. decline of injury—Positive after-effect—Stimulation of nerve by thermal. shocks—Enhancement of normal response after tetanisation — Untenability of theory of evolution of carbonic acid—Abnormal positive response converted into normal negative after tetanisation—Gradual transition from positive to negative, through intermediate diphasic— Effect of depression of tonicity on excitability and conductivity—Con- version of abnormal into normal response by increase of stimulus-intensity —Cyclic variation of response under molecular modification . , - 456

Specialised conducting tissues—Isolated vegetal nerve—Method of ob- taining electrical response in vegetal nerve—Similarity of responses of plant and animal nerve: (a) action of ether—(4) action of carbonic acid—(c) action of vapour of alcohol—(d) action of ammonia—(e) ex- ‘ hibition of three types of response, negative, diphasic and positive— (/) effects of tetanisation of normal and modified specimens—Effect of increasing stimulus on response of modified tissue ‘ ; : . 468

Receptivity, conductivity, and responsivity—Necessity for distinguishing these—Advantages of the Method of Balance —Simultaneous comparison of variations of receptivity, conductivity and responsivity—The Conductivity Balance—Effect of Na,CO, on frog’s nerve—Effect of CuSO,—Effect of chemical reagents on plant nerve—Effect of CaCl, on responsivity— ‘Responsivity variation under KCl—Comparison of simultaneous effects of NaCl and NaBr on responsivity—Effects of Na,CO, in different dilutions on conductivity—Demonstration of two different elements in conductivity, velocity and intensity—Conductivity versus responsivily— (a) effect of KI—(é) Effect of NaI—Effect of alcohol on receptivity, conductivity, and responsivity Comparison of simultaneous effects of alcohol—(a) on receptivity verses conductivity-~ (4) on receptivity Versus responsivity... : : : , : ps reas , . -. 479

Effect of temperature in inducing variations of conductivity : (@) by Method of Mechanical Response ; (4) by Method of Electric Balance—Effect of cold—Effect of rising temperature—The Thermal Cell—After-effect of stimulation on conductivity—The Avalanche Theory—Determination of after-effect of stimulus on conductivity by the Electrical Balance —After- effects of moderate stimulation—After-effect of excessive stimulation Current assumption of non-motility of nerve—Shortcomings of galvano- metric modes of detecting excitation— Mechanical response to continuous electric shocks—Optical Kunchangraph—Effect of ammonia on the mechanical response of nerve—Effect of morphia—Action of alcohol— Of chloroform—Abnormal positive or expansive response converted into normal contractile through diphasic, after tetanisation—Similar effects in mechanical response of vegetal nerve—Mechanical response due to

- transmitted effects of stimulation—Determination of velocity of trans- mission—Indeterminateness of velocity in isolated nerve—Kunchan- graphic records on smoked glass—Oscillating recorder— Mechanical response of afferent nerve—Record of mechanical response of nerve due to transmitted stimulation, in gecko—Fatigue of conductivity —Conver- sion of normal contractile response into abnormal expansive, through Great sensitiveness of the high magnification Kunchangraph—Individual contractile twitches shown in tetanisation of nerve—Sudden enhance- ment of mechanical response of nerve on cessation of tetanisation— Secondary excitation— Multiple mechanical excitation of nerve by single strong stimulation—Multiple mechanical excitation of nerve by drying .

Variation of resistance in Dionea, by ‘ modification’—Excitatory change, its various independent expressions—Characteristic difficulties of investi- gation—Morographic record by variation of resistivity—Inversion of curves at death-point—-Similarities between mechanical, electro-motive and resistivity curves of death—The true excitatory effect attended by diminution of resistance—Response of plant nerve by resistivity varia- tion—Independence of resistivity and mechanical variations—Responsive resistivity variation in frog’s nerve, and its modification under anzesthetics 540

Feeble conducting power of cortical tissues—Heliotropic and geotropic effects dependent on response of cortical tissues only— Phenomenon of correlation—Excitability of tissue maintained in normal condition only under action of stimulus—Physiological activities of growth, ascent of sap, and motile sensibility, maintained by action of stimulus—Critical importance of energy of light—Leaf-venation a catchment-basin-—Trans- mission of energy to remotest parts of plants—Plant thus a connected and organised entity . , ? : , , P ; ; . 551

Extra-polar effects of electrotonic currents on vegetal nerve —Electrotonic variation of excitability— Bernstein’s polarisation decrement—Hermann’s polarisation increment— Investigation into the law of electrotonic varia- tion of conductivity—Investigation on variation of excitability--Con- ductivity enhanced when excitation travels from places lower to higher electric potential, and depressed in opposite direction—When feeble, anode enhances and kathode depresses excitability—All electrotonic phenomena reducible to combined action of these factors—Explanation of apparent anomalies . > , ; ; : ; : , . 560

Reversal of Pfliiger’s Law under high E.M.F.—Similar reversals under feeble E.M.F.—Investigation by responsive sensation—Experiments on living wounds— Under moderate E.M.F., intensity of sensation enhanced at kathode, and depressed at anode—Under feeble E.M.F., sensation intensified at anode and depressed at kathode Aas {apaeernre of electrical currents in medical practice s : : ¢ : ; ‘ »'s 578 Two opposite responsive manifestations, negative and positive—Such

opposite responses induced by polar effects of currents of different signs —Arbitrary nature of term ‘ excitatory ’"—Pro-excitatory and anti-excita- tory agents—Molecular distortion under magnetisation in magnetic sub- stances—Different forms of response under magnetic stimulation— Mechanical, magneto-metric, and electro-motive responses—Uniform magnetic responses—Response exhibiting periodic groupings—TIneffec- tive stimulus made effective by repetition—Response by resistivity-

variation— Molecular model—Response of inorganic substance to electric radiation—Effect of rise of temperature in hastening period of recovery and diminishing amplitude of response—Sign of response reversed under feeble stimulation—Conduction of magnetic excitation—The Magnetic Conductivity Balance—Effect of A-tonus.and K-tonus, on excitability and conductivity—Conducting path fashioned by stimulus—Transmission of excitation temporarily blocked in iron wire, as in bporisar 7 nerve—

Anomalies of response—Explicable only from consideration of antecedent molecular changes—Continuous transformation from sub-tonic to hyper- tonic .conditions—Two methods of inquiry, first by means of character- istic curves, second by progressive change of response—Abnormal re- sponse characteristic generally of A or sub-tonic state—Abnormal trans- formed into normal, after transitional B state—B state characterised by staircase response—Responses at C stage normal and uniform—At stages D and E responses undergo diminution and reversal—Responsive pecu- liarities seen during ascent of curve, repeated in reverse order during descent—All these peculiarities seen not only in living but also in in- organic substances, under different methods of observation—Elucidation of effect of drugs—Response modified by tonic condition and past history . F : 3 ; , : , ; é ; . OFS

Indications of stimulatory changes in nerve : 1, Electrical ; 2, Mechanical— Transmission in both directions—Stimulatory changes in motor and sensory nerves similar— Responsive molecular changes and the correlated tones of sensation—Two kinds of nervous impulse, and their character- istics— Different manifestations of the same nervous impulse determined by nature of indicator-—Electrical, motile, and sensory responses, and their mutual relations—The brain as a perceiving apparatus—Weber- Fechner’s Law—Elimination of psychic assumption from explanation of - particular relation between stimulus and resultant sensation—Explana- tion of the factor of quality in sensation—Explanation of conversion from positive to negative tone of sensation after tetanisation—Various effects of progressive molecular change in nerve—Effects of attention and inhibi- tion—Polar variations of tonus, inducing acceleration and retardation . 644

Conversion of pleasurable into painful sensation, and vice versa, by electro- tonus—The Sensimeter—Mechanical stimulation—Stimulation by ther- mal shocks—Chemical stimulation—Opposite effects of anode and kathode—Normal effects reversed under feeble E.M.F. —Negative tone of sensation blocked by alcohol and anzesthetics—Separation of positive and negative sensations, by lag of one wave behind the other—Dissocia- tion of sensation by depression of conductivity—A bolition of the negative or painful element by block of conduction . ; : : ; . 666

a, ; a ; _ oe -s = i ; . 7 : F 2 Pes pS nb pease fio ation Pai? : ‘ , A , Sako ' 4° as. bet get s Te re fuices > rs Ri ” all . ? * j at . Lae = visa iE Le a PA na 2 Be 5 teh = itt >. ix aeeahe Giant ved ee Wiest sak “eh atte s nae cd Fatigue in the Electric Response of Metals . ; Stimulating Action of Na,CO, on Electric Response of Siatinum Abolition of Response in Metal by Oxalic Acid Arrangement for observing Simultaneous Mechanical aa Flectrical Responses ;

Photographic Record of Electrical Response by Galvanometric Negativity of Pulvinus of J/mosa, when leaf is_ physically restrained from falling : . Se Complete Apparatus for Method of Block a Nitcators Stinrulation . Influence of Suddenness on the Efficiency of Stimulus . iets Spring Attachment for obtaining Vibration of Uniform Rapidity Photographic Record of Uniform Response in Peiiole Fe em to transmitted excitation Taps of increasing strength I : 2: 3: “4 sadectan ep obey Sibente |

Increased Response with Increasing Vibrational Stimuli (Caulifiower- stalk) ‘ Responses to Indicating Stimulus obtuined: with’ Two Rpeelneas of Stalk of Cauliflower Photographic Record of Genesis of Tetanus in Methaeieal Response of Plants (Style of Datura alba) ‘ ee Response of (a) quickly reacting Amaranth ; (6) of iia Coletta Curve showing Rise and Fall of Rc aesive E, M. Change: onder moderate stimulation Response Curve from Rheotomic ch eee in Sin sf tuarcith under strong stimulation . :