Chapter XXI: Appendix: Mathematical and Physical Notions35 (2)

We can generalise these statements so that they will apply not only to a heat-engine but to all mechanisms which effect energy-transformations. In all such transformations entropy is generated. Therefore _the Entropy of the Universe tends to a maximum_.

AVAILABLE AND UNAVAILABLE ENERGY

Consider the Carnot engine as a perfect mechanism. It takes heat-energy from a source at a temperature _T_↓{2}°, and it gives up heat to a refrigerator at a temperature _T_↓{1}°_, _T_↓{2}° being greater than _T_↓{1}°. In the adiabatic expansion 1→2 the gas continues to expand until its temperature becomes equal to that of the refrigerator. It cannot, then, expand and do work any longer, and thus the proportion of the heat, _Q_↓{2}, received from the source, which can be converted into work, depends on the difference of temperature _T_↓{2}° - _T_↓{1}°. The greater is this difference the greater will be the proportion of the heat-energy received which can be converted into work. If the engine were a perfect one, and if the gas were also a perfect one (that is a gas which would continue to expand according to the equation for the adiabatic expansion of gases), and if the refrigerator were absolutely cold, then _all_ the heat energy received from the source could be converted into work.

We cannot produce a refrigerator of absolute temperature 0°, and therefore only a certain proportion of the heat which is received by the engine can be transformed into mechanical work. But this work can be used to reverse the action of the engine, and thus the same fraction of the total heat-energy which was given to the refrigerator can be taken from it and given back to the source. The perfect engine is therefore reversible without loss of available energy.

Now consider still the engine as a mechanism which takes heat from a source and gives it to a refrigerator, but let it be an actual engine. Instead of giving up a certain fraction of the heat received to the refrigerator--a fraction equal to _Q_↓{1} (_T_↓{1}°/_T_↓{2}°), it gives up rather more, because it is not a perfect mechanism, that is, it generates friction, etc. Some of the heat received thus ceases to be available for the performance of work; and passes into the refrigerator. The fraction of the heat-energy which passes into the refrigerator in the perfectly reversible engine was unavailable energy in the conditions in which the mechanism worked, or was imagined to work, but in the actual engine this fraction is increased. If we divide the increase of unavailable energy by the temperature of the refrigerator, the product is the increase of entropy generated in the actual engine over that generated in the ideal engine. Because of this reduction of available energy the actual engine is an irreversible mechanism.

This is the connection between unavailable energy and entropy. In all transformations some fraction of the transforming energy becomes heat, and this heat flows by conduction and radiation into the surrounding bodies. In general this heat simply raises the temperature of the medium into which it flows, and becomes unavailable for further transformations. With every transformation that occurs some part of the energy involved becomes unavailable. Therefore although the sum of the available and unavailable energy of the Universe remains constant, the fraction of unavailable energy tends continually to a maximum.

INERT MATTER

We can see now what is indicated by Bergson’s “inert matter.” It is not matter deprived of energy--such an expression has no meaning--_it is energy which is unavailable for further transformations_.

The matter in which we choose to say that this energy is inherent has become _inert_. Let us substitute for the Carnot engine the actual steam-engine of a ship, the condenser of which is cooled by the sea water which is taken in, and which is then heated and flows out again into the sea. The heat derived from the source, that is, from the furnace of the boiler where coal is burned to raise steam, thus passes out into the sea. Now the heat capacity of the sea is so great that the temperature of the water is not appreciably raised by this heat, which drains into it from the engine: even if it were appreciably raised, the heat would be conducted into the earth, or would be radiated out into space, and would then raise the temperature of the material bodies of the universe. But let all this heat remain in the sea. It then simply raises the temperature of the water by an exceedingly small amount, and the motions of the molecules become infinitesimally increased. But the heat becomes equally distributed by conduction and convection throughout the mass of the water in the sea, and as there are no differences in adjacent parts there are no means whereby the energy which thus passes into the sea can be again transformed.

A new order of things is the result of the processes we have indicated. The segregated, available heat-energy of material bodies has become transferred to the un-co-ordinated, diffuse, unavailable energies of the molecules which compose these bodies. The transformations which we can effect depend on the condition that the energy which we utilise is that of aggregates of molecules which are in a different physical condition, as regards this energy, from adjacent aggregates. But when this energy becomes equally distributed among the molecules of all the aggregates, the matter in which it inheres becomes inert. If we could, by a sorting process like that of Maxwell’s hypothetical demons, a process which does not expend the energy with which it deals, separate the molecules which were moving slowly from those which were moving more quickly, we could make this energy again available. But it must clearly be understood that our physics is the physics not of individual molecules, but of aggregates of molecules.

INDEX

Absolute, Driesch’s theory of, 47.

Acceleration (in physics), 355.

Acquired characters induced by the environment, 216;
a means of transformism, 220;
evidence of transmission scanty, 225;
transmission not inconceivable, 226.

Actions, categories of, and consciousness, 282;
deliberative, 283;
mechanistic hypothesis of, 157;
stereotyped, 283;
at a distance, 304.

Activation of the ovum, 176.

Adaptability, indicative of dominance, 258.

Adaptation, 217;
and acquired characters, 219;
and changes of morphology and function, 219;
not inherited, 220;
causes of, 239.

Adaptive response, 219.

Adiabatic changes, 361.

Aggregates, molecular, 353.

Algæ, distribution of, 260.

Allelomorphs, Mendelian, 231.

Alternation of generations, 175.

Amido-substances, 88.

Anabolism, 88.

Anatomical parts, homologies of, 251.

Animal action, considered objectively, 278.

Animal and plant contrasted, 269.

Animality, 269.

Annectant forms of life, 253.

Annelids, morphology of, 248.

Anthropomorphism in theories of action, 148.

Anti-enzymes, 94.

Antitoxins, 36.

Ants, a dominant group, 260.

Appendix vermiformis, 250.

Approximation, standards of, 347.

Armoured animals, 263.

Arthropods, morphology of, 249;
a dominant group, 259;
distribution, 260;
musculature of, 275;
adaptations for mobility, 275;
limits to size of, 275.

Assimilation, 67.

Atoms, constitution of, 355;
arrangements of, 353.

Automatism of animals deduced from mechanistic theories, 280.

Autonomy in development, 322.

Available energy, 62;
and entropy, 374.

Bacteria, a dominant group, 259;
distribution, 259;
geological history, 259, 261;
morphology, 268;
metabolism, 266;
specialisation, 263;
parasitism, 259;
nitrogen, 73;
prototrophic, 119, 266;
paratrophic, 266;
putrefactive, 266;
fermentation, 266;
and Brownian movements, 119;
compensatory to plants, 267.

Bergson, 28;
creative evolution, 244;
duration, 154;
animals and plants, 78;
eye of Pecten, 234;
inert matter, 375;
infinitesimal analysis of the organism, 111;
kinematographic analysis, 110;
theory of intellectualism, 51;
memory, 156;
morphological themes, 250;
theory of pain, 281;
theory of perception, 7, 10;
the vital impetus, 318.

Biology, systematic, 201, 203.

Biophors, 132;
size of, 183;
growth of, 185.

Biotic energy, 325.

Borelli and animal mechanism, 125.

Brownian movement, 118;
significance of, 119.

Bryan and thermodynamics, 62.

Bud-formation, 165.

Calculus, infinitesimal, 25, 115, 350.

Calorimetric experiments, 65, 68.

Capacity-energy factors, 61.

Carnot’s cycle, 69, 78, 113;
negative, 368;
description of, 363, 366;
compared with plant metabolism, 75;
compared with the organism, 73.

Catalysis, 90;
universality of, 91.

Catalysts, characters of, 91.

Categories of organisms, 209.

Central nervous system, specialisation of, 273;
a switchboard, 273;
evolution of, parallel with evolution of muscular system, 281.

Chance in evolution, 237.

Chemical affinity, 361.

Chemical energy, degradation of, 75.

Chemical reactions, direction of, 78;
exothermic, 86;
explosive, 86;
similar in organic and inorganic systems, 78.

Chemical synthesis, involve vital activity, 318.

Chemistry, medieval, 125.

Chlorophyll, 69.

Chlorophyllian organisms, 88;
metabolism of, 265;
a dominant group, 259;
essential morphology of, 268;
distribution of, 260.

Chromatin of the nucleus, 130;
the material basis of inheritance, 182.

Chromosomes, 130, 182, 183.

Classification of organisms, 209.

Classificatory systems, are artificial arrangements, 289;
suggest evolutionary process, 210.

Clausius, 54;
and Carnot’s Law, 113.

Cœlenterates, morphology of, 248.

Cœlomate animals, 256.

Colloidal platinum, 91.

Colloids, 107.

Colonial organisms, 164.

Comparative anatomy, task of, 251.

Compensatory energy-transformations effected by life, 309.

Conjugation, 173;
and heredity, 176;
a stimulus to growth, 175.

Consciousness involves analysis of the environment, 11;
analysis of, is an arbitrary process, 12;
a feeling of normality, 6;
a part of crude sensation, 40;
simplified by reasoning, 41;
an intensive multiplicity, 303;
degree of, is parallel to development of sensori-motor system, 280;
not existent outside ourselves, 278;
not a function of chemico-physical mechanism, 160;
intense in difficultly performed operations, 281;
and activity of cerebral cortex, 281;
absent in parasites, 291.

Conservation a test of reality, 357.

Conservation of energy, 52;
in organisms, 83.

Conservation of structure, 253, 256.

Constants, mathematical, 344.

Continuity of cells in embryo, 171.

Contractility, 100;
muscular, 103.

Co-ordinates, systems of, 23.

Corals, 164.

Cosmic evolution, 314;
is a tendency towards degradation of energy, 316.

Creation, special, 214.

Curvature, 27.

Curves, isothermal and adiabatic, 362.

Cuttle-fishes, 250.

Cytoplasm, 130.

Darwin, and natural selection, 221;
acquired characters are inherited, 220;
hypothesis of pangenesis, 181.

Death, is catastrophic katabolism, 340.

Degradation of energy, 81.

Deliberation and consciousness, 281.

Demons, Maxwell’s, 116.

Descartes and mechanism, 121;
the rational soul, 123, 318;
his physiology, 122;
his spiritualism, 124;
and animal automatism, 125.

Descent, collateral, 257.

Determinants in embryology, 132, 183;
arrangement of, 184;
latent in regenerative processes, 142.

Development, organisation in, 128;
parthenogenetic, 176;
reverses inorganic tendencies, 324;
impossibility of chemical hypotheses, 141;
is the assumption of a mosaic structure, 301;
blastula stage in, 129;
gastrula stage in, 130;
pluteus stage in, 140;
individual, 300.

Developmental systems prospective value of, 138;
prospective potency of, 138.

Diatoms, 163;
distribution of, 260.

Differential elements, 115.

Differentiation in development, 170.

Diffusion in the animal body, 95.

Digestion, 67;
chemistry of, 72.

Dinosaurs, an unsuccessful line of evolution, 275.

Dissipation of energy, 114;
in physical mechanisms, 59;
by the organism, 68, 79.

Distribution of organisms, 262;
limits to, 259;
indicative of dominance, 258.

Diversity, physical, 54;
effective and ineffective, 115.

Dominance in geological time, 258;
implies long geological history, 261;
Mendelian, 196.

Dominant organisms, 258, 259, 264.

Driesch natural selection, 229;
analytical definition of the organism, 331;
entelechy, 318;
experimental embryology, 134;
historical basis of reacting, 154;
logical proof of vitalism, 136;
proof of vitalism from behaviour, 153;
theory of the absolute, 47.

Duration, 28;
duration and time illustrated, 30;
illustrated by immunity, 35;
more than memory, 155;
a factor in responding, 155.

Ecdysis, 276.

Echinoderms, morphology of, 248.

Ectoderm, 177.

Effector organs, 158, 271.

_Élan vital_, 161.

Electromagnetism, 355.

Electrons, 304, 355.

Elimination, natural, 229.

Embryological stages compared with physical phases, 308.

Embryology, 127;
hypotheses of, 128;
physical hypotheses fail, 128;
experimental, 128;
suggests phylogenetic history, 213.

Emulsoids, 108.

Endoskeleton, 177, 276.

Energetics, first law of, 51;
second law of, 113.

Energy, 356;
available and unavailable, 55;
biotic, 325;
chemical, 61;
and causation, 54;
degradation of, 63;
dissipation of, 53;
electrical, 61;
forms of, 325;
kinetic, 52, 357;
mechanical, 60, 61;
potential, 53, 358;
of position, 360.

Energy-transformations, 54, 371;
anabolic, 89;
in the animal, 70;
compensatory, 88;
compensatory organic, 268;
irreversible, 59;
in physical mechanisms, 58;
in the plant, 71.

Engelmann, and the artificial muscle, 105.

Entelechy, 161, 318;
not energy, 329;
is power of direction, 329;
not spatial but acts into space, 330;
an intensive manifoldness, 330;
is arrangement, 323;
involves regulations, 323;
arrests inorganic happening, 327;
initiates chemical happening, 327;
compared with enzyme action, 327;
illustrated by analogy, 322.

Entropy, 54;
augmentation of, 75;
and Carnot engine, 369.

Environment, does not select variations, 235;
made by the organism, 236.

Enzymes, 90;
nature of, 92;
pancreatic, 93;
reversible, 93;
activation of, 92.

Enzyme activity, 93.

Epigenesis in development, 129.

Equilibrium, chemical, 102.
false, 86, 151.

Ether of space, 46, 304, 361;
potential energy resides in, 361.

Evolution tendencies of, 252, 264, 276, 295;
separation of tendencies, 296;
a transformation of intensive into extensive manifoldness, 309;
a dissociation of tendencies originally coalescent, 305;
increases diversity, 310;
segregates energy, 311;
compared with permutations and combinations, 301;
a series of phases in a transforming system, 298;
a logical hypothesis, 214;
parallel processes in, 234;
geological time inadequate for, 237;
side paths in, 262;
mechanistic hypotheses inadequate, 237;
cosmic, 214, 297, 314;
of the crust of the earth, 264.

Excretory products, 269.

Exoskeleton, 276.

Exothermic reactions, 86.

Experience and duration, 156.

Experimental biology proves evolution, 246.

Explosive reactions, 101.

Extension in space, 18.

Extinct groups, 263.

Fats, digestion of, 93.

Fecundity of animals, 179, 239.

Ferments, 92.

Fertilisation (in reproduction), 176.

Finalism, 216.

Fishes, distribution of, 261.

Fluctuating variations, 200.

Food-stuffs, absorption of, 89.

Force, 354.

Form, accidental and essential, 167, 353;
geological, 168;
crystalline, 168.

Frequency distributions, 22, 187, 350.

Frog, development of egg of, 131.

Functionality, 343;
in physical systems, 307.

Galvanotropism, 145.

Gases, compression of, 362;
kinetic theory of, 117, 361.

Gastrea-theory, 177;
illustrated, 255;
limitations of, 256.

Genera, stability of, 186.

Geometry, Cartesian, 25;
Euclidean, 19, 25;
perceptual and conceptual limits, 21.

Geotropism, 144.

Germ-cells, 175;
and soma, 179.

Germinal selection, 241.

Germ-layers, 177;
theory of, 256.

Germ-plasm, a mixture, 240;
stability of, 240.

Givenness, 47.

Gonads, 179.

Growth law of, in the organism, 172;
by accretion, 169;
by ecdysis, 276;
geometrical, 169;
physical, 167;
of crystals, 167;
and differentiation, 170;
variability of, 172.

Haeckel, the Gastrea-Theorie, 177, 254.

Harmonic analysis, 11.

Harvey, and the circulation of the blood, 121.

Heat, flow of, 117;
production of, in physical changes, 114.

Heliotropism, 144.

Heredity, 181.

Hertzian waves, 355.

Homoiothermic animals, 67.

Hormones, 225.

Human activity, tends to arrest dissipation of energy, 312.

Huxley, 84;
and mechanistic biology, 127;
and the physical basis of life, 113;
and mechanism, 106;
and universal mathematics, 215.

Hybrids, Mendelian, 196;
infertility of, 195;
between Linnean species, 194.

Hydra, regeneration of, 162.

Idants, 183.

Idealism founded on pure reasoning, 45;
of Berkeley, 45.

Ids, 183.

Immunity, 35.

Individual, 162;
definition of, 167.

Individuality, orders of, 163;
physical concept of, 165;
morphologically an artificial concept, 166;
in societies, 171.

Inertia, 354.

Infinity, a definition of, 342.

Inorganic happening abolishes diversity, 310.

Instinct, a problem for naturalists, 283;
an inheritable adaptation of behaviour, 287.

Instinct and intelligence, 283;
distinction not absolute, 294;
may coexist, 306.

Instinct and functioning, 286.

Instinctive actions not necessarily unconscious, 283;
not learned, 286;
not necessarily perfect, 284;
effective from the first, 285;
capable of improvement, 285.

Intelligent actions, non-inheritable adaptations of behaviour, 287;
involve deliberation, 50, 287;
involve conscious relations with the environment, 288;
involve use of tools, 284.

Intensity-factors, 61.

Intensive multiplicity, 303.

Irreversibility, 62.

Irritability, 100.

Isothermal changes, 361.

James, William (and academic philosophies), 80.

Jennings, and physiological states, 154;
behaviour of Protozoa, 293;
animal movements, 149;
the avoiding reaction, 149.

Katabolism, 90.

Kinases, 92.

Kinematographic analysis, 316.

Lamarck, hypotheses of evolution, 220.

Lamarckian inheritance, an inadequate cause of transformism, 227.

Lankester, acquired characters not inherited, 221.

Laplace, and universal mathematics, 215.

Laplacian mind, 299.

Larval stages, 170.

Latency (of characters), 195.

Lavoisier, and chemistry of the organism, 127.

Life and adaptation to physical conditions, 338;
and reversibility, 339;
a direction of energies, 341;
defined energetically, 337;
cosmic origin of, 338;
physical conditions for, 338;
limited in power, 306;
sparsity of, on the earth, 306;
tends to arrest dissipation of energy, 314;
its origin a pseudo-problem, 337.

Life-substance, the primitive, 301.

Locomotion, 258.

Loeb and the associative memory, 155;
and artificial parthenogenesis, 176;
mechanism and life, 127;
stereotropism, 19;
theory of tropisms, 144;
tropistic movements, 146;
theories of heredity, 181.

Limit, the mathematical, 346.

Limits to perceptual activity, 23.

Links, missing, 252.

Linnean species, 201.

Manifoldness, intensive, 302.

Mass, 353.

Mass action, 140.

Materialism, 85.

Mathematics, evades consideration of time, 35.

Matter, 353;
inert, 375;
notion of is an intuitive one, 352.

Maxwell, and sorting demons, 116, 377.

Mayow, and chemical physiology, 126.

Mechanical work, done by the animal, 67;
not done by the plant, 71.

Mechanism, organic and inorganic, 78;
the thermodynamic, 66;
radical, 215;
in life, 121.

Membranes, semi-permeable, 95.

Memory, 39;
a possible cerebral mechanism of, 158;
mechanistic hypotheses impossible, 157.

Mendelism, 196;
a logical hypothesis, 199;
terminology is a symbolism, 198;
analogy of unit characters with chemical radicles, 197;
transmission of characters of, 230.

Mesoderm, 177;
origin of, 255.

Metabolism, 37, 88, 209;
analytic, 269;
of animals, 65, 67;
constructive, 269;
destructive, 269;
direction of, 69;
in green plant, 70, 75;
intra-cellular, 99;
integration of its activities, 111;
rôle of oxygen in, 105;
specialisation of during evolution, 305;
synthetic, 269.

Metaphysics of science, 45.

Metazoan animals, 162.

Mitosis, 182.

Mobility, organic, 269;
structural adaptations tending to, 275.

Modifications of structure adaptive and non-adaptive, 251.

Molecules, 353;
size of, 116;
in a gas, 115;
aggregations of, 108.

Molluscs, morphology of, 249.

Morgan, and physico-chemical mechanisms, 128, 143.

Morphogenesis, 257.

Morphological evolution, tendencies of, 295.

Morphological structures degeneration of, 251;
suppression of, 250;
coalescence of, 250;
replacement of, 250;
specialisation of, 250;
change of function of, 251.

Morphology, 209;
a basis of classification, 210;
relates groups of organisms, 211;
distinctions of, not absolute, 285, 290;
generalised, 250;
suggests blood relationships, 213;
schemata of, 249, 291;
cannot be considered apart from physiology, 285.

Mosaic-theory of development, 131.

Motion not an intellectual concept, 27;
not considered in Euclidean or Cartesian geometry, 26;
bodily motion is absolute, 24;
outside ourselves is relative, 24.

Motor-habits, 38, 155.

Multicellular organisms, evolution of, 223.

Muscular contraction, 104;
metabolism in, 104;
heat production in, 104.

Muscular and nervous organs, 275.

Musculature and weight of body, 275.

Mutations, 189;
essential nature of, 193;
causes of, 200;
must be co-ordinated, 231;
physical model of, 192;
the material for selection, 230.

Nägeli, and autonomy in development, 160.

Natural selection, 228;
generality of, 229;
a slow process, 230.

Nebulæ, 315.

Nebular hypothesis, 296.

Nerve impulses, 100;
velocity of, 101;
integration of, 273.

Nervous system, 272;
in co-ordination of activities, 171;
paths in, 157.

Nervous activity, 107;
metabolism in, 107;
electric changes in, 107;
influence of metabolism on, 97.

Nothing, a pseudo-idea, 18.

Nucleus, evolution of, 222;
division of, 130, 182.

Ontogenetic stages, 255.

Orders of individuality, 171.

Organism, definition of, 331;
analysis of its activities, 109;
animal and plant, 76;
considered energetically, 77;
the dominant, 258;
a function of the environment, 216;
a mechanism, 51;
the primitive, 222;
a physico-chemical system, 65;
a thermodynamic mechanism, 104.

Organic chemical syntheses, 317.

Organisation in development, 137.

Organ-rudiments, 257.

Osmosis, 95, 99.

Ostracoderms, 291.

Ostwald on catalysis, 91.

Ovum, development of, 129;
maturation of, 198, 239;
an intensive manifoldness, 302.

Oxidases, 105.

Oxygen in metabolism, 69.

Pain, Bergson on, 281.

Palæontology, 210;
relates groups of organisms, 211.

Pangenesis, 181.

Paramœcium, division of, 173, 175;
responses of, 4.

Parasitism, 259;
tends to immobility, 290.

Parthenogenesis, 176;
artificial, 176.

Particles, 356.

Pecten, eye of, 233.

Perception
not merely physical stimulation, 7;
involves effector activity, 7;
involves deliberative action, 9;
arises from acting, 50;
and choice of response, 155;
is unfamiliar cerebral activity, 8;
skeletonises consciousness, 40.

Peridinians, 77, 163;
distribution of, 260.

Personal equation, 45.

Personality, 167;
an intuition, 167;
division of, 173;
is absolute, 48.

Pflüger, and experimental embryology, 131.

Phases in physical systems and organic systems, 321;
in transforming systems, 308.

Phenomenalism, 46.

Photosynthesis, 70, 76, 86.

Phototaxis, 144.

Phyla
animal, 247;
morphology of, 247;
relations between, 252;
ancestries of, 252.

Phylogenies, 253;
are summaries of morphological results, 254;
indicative of directions of evolution, 254;
criteria of, 253.

Phylogeny, 246.

Phylum, 210.

Physical basis of life, 84.

Physico-chemical reactions, 80;
are directed, 118;
the means of development and behaviour in the organism, 160.

Physico-psychical parallelism, 160.

Physics, a statistical science, 116, 377.

Physiology
Galenic, 122;
an analysis of organic activity, 120, 328.

Plants, geological history of, 261;
characterised by immobility, 277;
contrasted with animals, 277.

Platonic ideas, 204.

Platyhelminths, morphology of, 248.

Poikilothermic animals, 68.

Poincaré, and Brownian movement, 119.

Polar bodies, 198.

Polyzoa, 164.

Porifera, 248.

Potential, 61.

Potential energy, 58, 114.

Preformation an embryological hypothesis, 128.

Probability, 350.

Proteids, digestion of, 90.

Proto-forms, 254.

Protoplasm, nature of, 106;
artificial, 106;
disintegration of, 107;
activities of, 107;
similar in plant and animal, 294.

Protozoa, 247;
behaviour of, 293.

Pterodactyls, 274.

Races (in specific groups), 194.

Radiation, 355;
of sun, 51;
transformation of energy of, 57.

Radio-activity, 56, 359.

Reality, objective, 43.

Reception, 3;
organs of, 271;
by specialised sense-organs, 11.

Recessiveness, Mendelian, 196.

Reflex action, 4, 272;
concatenated, 150;
a complex series of actions, 6;
not necessarily accompanied by perception, 155;
the basis of instincts, 150;
a schematic description, 5;
in decapitated frog, 6;
frictionless cerebral activity, 8;
involves a limited part of the environment, 50.

Reflex arcs, 272.

Regeneration, 142;
in Hydra, 164;
in sea-urchin embryo, 164;
in Planaria, 164.

Regression, 189.

Reinke, and structure of protoplasm, 106.

Reintegration in development, 171.

Rejuvenescence, 175.

Releasing agencies, 157.

Reproduction, 167;
asexual, 175;
by brood-formation, 173;
by conjugation, 173;
sexual, 174;
by division, 172;
compared with minting machine, 242;
of the tissues, 180.

Responses of organisms, 217;
directed, 269;
of magnet, 279;
of green plant, 279.

Reversibility, physical, 369.

Rodewald, chemical nature of protoplasm, 106.

Roux, experimental embryology, 131;
development the production of a visible manifoldness, 307.

Saliva, secretion of, 96.

Salivary glands, metabolism of, 96.

Salivary secretion, not a purely mechanistic process, 112.

Sea, not really rich in life, 306.

Sea-urchin gastrula, 170.

Secretion described mechanistically, 98.

Secretion, psychical, 99.

Segmentation of the ovum, 129.

Selection, natural, 228;
from fluctuating variations, 189;
from mutations, 190.

Semon, mnemic hypothesis of heredity, 181.

Senescence, 175.

Sensation, 2;
analysis of, 13.

Sense-receptors and the idea of matter, 352.

Sensori-motor system, 270;
dominant in animals, 271, 273;
specialisation of, 271, 273;
essentially the same in all animals, 294;
absent in plants, 269;
vestigial in some parasites, 290.

Sexuality, 174.

Siphonophores, regeneration in, 163.

Size of animals, 274.

Skeleton of vertebrates, 276;
of arthropods, 276;
and mobility, 276.

Soddy, and chemical energy, 361.

Soma, 179;
evolution of, 223.

Space, form of, 18;
3-dimensional, 18;
3-dimensional space an intuition, 19;
2-dimensional, 19;
the form of, depends on modes of activity, 21, 25.

Species, are categories of structure, 201;
comparison with Platonic ideas, 204;
criteria of, 202;
elementary, 193;
are intellectual constructions, 203;
individuality of, 203;
Linnean, 201, 289;
are phases in an evolutionary flux, 206;
are families in the human sense, 208;
systematic, 201.

Specific organisation, stability of, 186.

Stahl, and the phlogistic hypothesis, 126;
and vitalism, 126.

Stimuli, elemental, 151;
physico-chemical, 151;
formative, 176;
complex auditory, 152;
integration of, 152;
individualised, 152, 270;
contractile, 103.

Stimulus and response, functionality of, 152.

Substantia physica, 46, 355.

Surface tension, 105, 106.

Suspensoids, 108.

Sylvius, the organism a chemical mechanism, 125.

Symbiosis, 77.

Symbiotic organisms, 88.

Synapses, in central nervous system, 158, 272.

Synthetic chemistry, 236, 317.

System, isolated, 63.

Systems in development
equipotential, 139;
harmonious equipotential, 139;
complex equipotential, 140.

Taxis, 144;
no perception in, 155.

Telegraphy, wireless, 355.

Temperature of sun, 56;
of space, 57.

Thermodynamics, 51;
1st law of, 51;
2nd law of, 54, 63, 309, 316;
and Maxwell’s demons, 118;
laws of subject to limitations, 115.

Thermodynamical mechanism, the organism not a, 69.

Thomson, W., dissipation of energy, 113.

Time a series of standard events, 28;
astronomical, 34;
time differentials, 34.

Tissues, evolution of, 223.

Tools, nature of, 285;
use of must be learned, 285;
bodily, 285.

Toxins, 36.

Transformism, 213.

Trematodes, larval stages of, 165.

Trial and error, 293;
in reasoning, 293;
a hypothesis of animal movements, 150.

Trigger reactions, 87.

Trilobites, an ancient group, 261.

Tropisms, 144;
in plants, 269, 279;
in moths, 280;
and natural selection, 147;
and movements of caterpillars, 146;
an inadequate basis for a theory of animal movements, 147.

Tunicates, suppressed notochord of, 250.

Unavailable energy and entropy, 375;
tendency to increase of, 375.

Unicellular organisms, energy-transformations in, 177.

Unit-characters, 230.

Van’t Hoff’s law, 218.

Variability, 172, 186;
continuous, 188;
discontinuous, 188;
examples of, 187;
and the environment, 189;
independent of the environment, 239;
and growth, 188;
tendencies of, 235.

Variation, rate of (mathematical), 344;
in biology, 186;
atavistic, 195;
direction of, 233;
fluctuating, 189;
must be co-ordinated, 231;
mathematical probability of co-ordination of 233;
the material for selection, 229;
origin of, 230;
selected by the organism, 237;
cause of, a pseudo-problem, 242;
arise de novo, 244.

Variables (mathematical), 343.

Varieties, specific, 194.

Vegetable life, 265.

Vertebrates, 249;
adaptations securing mobility, 275;
ancestry of, 253;
morphology of, 249;
a dominant group, 259;
distribution of, 260.

Verworn, and mechanism in life, 127.

Vesalius, anatomical school of, 121.

Vital activities, integration of, 128;
co-ordination of, 171.

de Vries and mutations, 191;
fluctuating variations inherited, 220.

Vital force, 318.

Van der Waal’s equation, 308.

Weber’s law, 16;
a quasi-mathematical relation, 17.

Weismann, hypothesis of heredity, 182;
hypothesis of germinal selection, 241;
hypothesis of development, 132;
mosaic-theory, 131;
preformation hypothesis, 133;
hypothesis of the germ-plasm, continuity of the germ-plasm, 181;
germinal changes inconceivable, 224;
size of biophors, 183;
origin of life, 339;
spontaneous generation a logical necessity, 339.

Weismannism, a series of logical hypotheses, 320;
physico-chemical analogies, and subsidiary hypotheses, 223.

Whales, an unsuccessful line of evolution, 274.

Whitehead, and mathematical reasoning, 347.

Wilson, mosaic-theory of development, 139.

Yerkes, and behaviour of crustacea, 293.

Zymogens, 92.

Zymoids, 94.

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EDINBURGH

Spelling corrections:

animo-acids → amino-acids
animo-substances → amino-substances
differen tkinds → different kinds
algae → algæ
organsim → organism (x2)
diffusbility → diffusibility
marjoity → majority
hythothesis → hypothesis
execretory → excretory
conconsidered → considered

End of Project Gutenberg's The philosophy of biology, by James Johnstone