Chapter XXXIX: Epilogue (4)

[643] In this there lies a certain justification for a saying of Minot’s, of the greater part of which, nevertheless, I am heartily inclined to disapprove. “We biologists,” he says, “cannot deplore too frequently or too emphatically the great mathematical delusion by which men often of great if limited ability have been misled into becoming advocates of an erroneous conception of accuracy. The delusion is that no science is accurate until its results can be expressed mathematically. The error comes from the assumption that mathematics can express complex relations. Unfortunately mathematics have a very limited scope, and are based upon a few extremely rudimentary experiences, which we make as very little children and of which no adult has any recollection. The fact that from this basis men of genius have evolved wonderful methods of dealing with numerical relations should not blind us to another fact, namely, that the observational basis of mathematics is, psychologically speaking, very minute compared with the observational basis of even a single minor branch of biology .... While therefore here and there the mathematical methods may aid us, _we need a kind and degree of accuracy of which mathematics is absolutely incapable_ .... With human minds constituted as they actually are, we cannot anticipate that there will ever be a mathematical expression for any organ or even a single cell, although formulae will continue to be useful for dealing now and then with isolated details...” (_op. cit._, p. 19, 1911). It were easy to discuss and criticise these sweeping assertions, which perhaps had their origin and parentage in an _obiter dictum_ of Huxley’s, to the effect that “Mathematics is that study which knows nothing of observation, nothing of experiment, nothing of induction, nothing of causation” (_cit._ Cajori, _Hist of Elem. Mathematics_, p. 283). But Gauss called mathematics “a science of the eye”; and Sylvester assures us that “most, if not all, of the great ideas of modern mathematics have had their origin in observation” (_Brit. Ass. Address_, 1869, and _Laws of Verse_, p. 120, 1870).

[644] _Historia Animalium_ I, 1.

[645] Cf. _supra_, p. 714.

[646] Cf. Osborn, H. F., On the Origin of Single Characters, as observed in fossil and living Animals and Plants, _Amer. Nat._ XLIX, pp. 193–239, 1915 (and other papers); _ibid._ p. 194, “Each individual is composed of a vast number of somewhat similar new or old characters, each character has its independent and separate history, each character is in a certain stage of evolution, each character is correlated with the other characters of the individual .... The real problem has always been that of the origin and development of characters. Since the _Origin of Species_ appeared, the terms variation and variability have always referred to single characters; if a species is said to be variable, we mean that a considerable number of the single characters or groups of characters of which it is composed are variable,” etc.

[647] Cf. Sorby, _Quart. Journ. Geol. Soc._ (_Proc._), 1879, p. 88.

[648] Cf. D’Orbigny, Alc., _Cours élém. de Paléontologie_, etc., I, pp. 144–148, 1849; see also Sharpe, Daniel, On Slaty Cleavage, _Q.J.G.S._ III, p. 74, 1847.

[649] Thus _Ammonites erugatus_, when compressed, has been described as _A. planorbis_: cf. Blake, J. F., _Phil. Mag._ (5), VI, p. 260, 1878. Wettstein has shewn that several species of the fish-genus _Lepidopus_ have been based on specimens artificially deformed in various ways: Ueber die Fischfauna des Tertiären Glarnerschiefers, _Abh. Schw. Palaeont. Gesellsch._ XIII, 1886 (see especially pp. 23–38, pl. I). The whole subject, interesting as it is, has been little studied: both Blake and Wettstein deal with it mathematically.

[650] Cf. Sir Thomas Browne, in _The Garden of Cyrus_: “But why ofttimes one side of the leaf is unequall unto the other, as in Hazell and Oaks, why on either side the master vein the lesser and derivative channels stand not directly opposite, nor at equall angles, respectively unto the adverse side, but those of one side do often exceed the other, as the Wallnut and many more, deserves another enquiry.”

[651] Where gourds are common, the glass-blower is still apt to take them for a prototype, as the prehistoric potter also did. For instance, a tall, annulated Florence oil-flask is an exact but no longer a conscious imitation of a gourd which has been converted into a bottle in the manner described.

[652] Cf. _Elsie Venner_, chap. ii.

[653] This significance is particularly remarkable in connection with the development of speed, for the metacarpal region is the seat of very important leverage in the propulsion of the body. In the Museum of the Royal College of Surgeons in Edinburgh, there stand side by side the skeleton of an immense carthorse (celebrated for having drawn all the stones of the Bell Rock Lighthouse to the shore), and a beautiful skeleton of a racehorse, which (though the fact is disputed) there is good reason to believe is the actual skeleton of Eclipse. When I was a boy my grandfather used to point out to me that the cannon-bone of the little racer is not only relatively, but actually, longer than that of the great Clydesdale.

[654] Cf. Vitruvius, III, 1.

[655] _Les quatres livres d’Albert Dürer de la proportion des parties et pourtraicts des corps humains_, Arnheim, 1613, folio (and earlier editions). Cf. also Lavater, _Essays on Physiognomy_, III, p. 271, 1799.

[656] It was these very drawings of Dürer’s that gave to Peter Camper his notion of the “facial angle.” Camper’s method of comparison was the very same as ours, save that he only drew the axes, without filling in the network, of his coordinate system; he saw clearly the essential fact, that the skull _varies as a whole_, and that the “facial angle” is the index to a general deformation. “The great object was to shew that natural differences might be reduced to rules, of which the direction of the facial line forms the _norma_ or canon; and that these directions and inclinations are always accompanied by correspondent form, size and position of the other parts of the cranium,” etc.; from Dr T. Cogan’s preface to Camper’s work _On the Connexion between the Science of Anatomy and the Arts of Drawing, Painting and Sculpture_ (1768?), quoted in Dr R. Hamilton’s Memoir of Camper, in _Lives of Eminent Naturalists_ (_Nat. Libr._), Edin. 1840.

[657] The co-ordinate system of Fig. 382 is somewhat different from that which I drew and published in my former paper. It is not unlikely that further investigation will further simplify the comparison, and shew it to involve a still more symmetrical system.

[658] _Dinosaurs of North America_, pl. LXXXI, etc. 1896.

[659] _Mem. Amer. Mus. of Nat. Hist._ I, III, 1898.

[660] These and also other coordinate diagrams will be found in Mr G. Heilmann’s book _Fuglenes Afstamning_, 398 pp., Copenhagen, 1916; see especially pp. 368–380.

[661] Cf. W. B. Scott (_Amer. Journ. of Science_, XLVIII, pp. 335–374, 1894), “We find that any mammalian series at all complete, such as that of the horses, is remarkably continuous, and that the progress of discovery is steadily filling up what few gaps remain. So closely do successive stages follow upon one another that it is sometimes extremely difficult to arrange them all in order, and to distinguish clearly those members which belong in the main line of descent, and those which represent incipient branches. Some phylogenies actually suffer from an embarrassment of riches.”

[662] Cf. Dwight, T., The Range of Variation of the Human Scapula, _Amer. Nat._ XXI, pp. 627–638, 1887. Cf. also Turner, _Challenger Rep._ XLVII, on Human Skeletons, p. 86, 1886: “I gather both from my own measurements, and those of other observers, that the range of variation in the relative length and breadth of the scapula is very considerable in the same race, so that it needs a large number of bones to enable one to obtain an accurate idea of the mean of the race.”

[663] There is a paper on the mathematical study of organic forms and organic processes by the learned and celebrated Gustav Theodor Fechner, which I have only lately read, but which would have been of no little use and help to our argument had I known it before. (Ueber die mathematische Behandlung organischer Gestalten und Processe, _Berichte d. k. sächs. Gesellsch._, _Math.-phys. Cl._, Leipzig, 1849, pp. 50–64.) Fechner’s treatment is more purely mathematical and less physical in its scope and bearing than ours, and his paper is but a short one; but the conclusions to which he is led differ little from our own. Let me quote a single sentence which, together with its context, runs precisely on the lines of the discussion with which this chapter of ours began. “So ist also die mathematische Bestimmbarkeit im Gebiete des Organischen ganz eben so gut vorhanden als in dem des Unorganischen, und in letzterem eben solchen oder äquivalenten Beschränkungen unterworfen als in ersterem; und nur sofern die unorganischen Formen und das unorganische Geschehen sich einer einfacheren Gesetzlichkeit mehr nähern als die organischen, kann die Approximation im unorganischen Gebiet leichter und weiter getrieben werden als im organischen. Dies wäre der ganze, sonach rein relative, Unterschied.” Here in a nutshell, in words written some seventy years ago, is the gist of the whole matter.

An interesting little book of Schiaparelli’s (which I ought to have known long ago)—_Forme organiche naturali e forme geometriche pure_, Milano, Hoepli, 1898—has likewise come into my hands too late for discussion.

{780}

INDEX.

Abbe’s diffraction plates, 323

Abel, O., 706

Abonyi, A., 127

Acantharia, spicules of, 458

Acanthometridae, 462

Acceleration, 64

Aceratherium, 761

Achlya, 244

Acromegaly, 135

Actinomma, 469

Actinomyxidia, 452

Actinophrys, 165, 197, 264, 298

Actinosphaerium, 197, 266, 298, 468

Adams, J. C., 663

Adaptation, 670

Addison, Joseph, 671

Adiantum, 408

Adsorption, 192, 208, 241, 277, 357;
orientirte, 440, 590;
pseudo, 282

Agglutination, 201

Aglaophenia, 748

Airy, H., 636

Albumin molecule, 41

Alcyonaria, 387, 413, 424, 459

Alexeieff, A., 157, 165

Allmann, W., 643

Alpheus, claws of, 150

Alpine plants, 124

Altmann’s granules, 285

Alveolar meshwork, 170

Ammonites, 526, 530, 537, 539, 550, 552, 576, 583, 584, 728

Amoeba, 12, 165, 209, 212, 245, 255, 288, 463, 605

Amphidiscs, 440

Amphioxus, 311

Ampullaria, 560

Anabaena, 300

Anaxagoras, 8

Ancyloceras, 550

Andrews, G. F., 164;
C. W., 716

Anhydrite, 433

Anikin, W. P., 130

Anisonema, 126

Anisotropy, 241, 357

Anomia, 565, 567

Antelopes, horns of, 614, 671

Antheridia, 303, 403, 405, 409

Anthoceros, spore of, 397

Anthogorgia, spicules of, 413

Anthropometry, 51

Anticline, 360

Antigonia, 750, 775

Antlers, 628

Apatornis, 757

Apocynum, pollen of, 396

Aptychus, 576

Arachnoidiscus, 387

Arachnophyllum, 325

Arcella, 323

Arcestes, 539, 540

Archaeopteryx, 757

Archimedes, 580;
spiral of, 503, 524, 552

Argali, horns of, 617

Argiope, 561

Argonauta, 546, 561

Argus pheasant, 431, 631

Argyropelecus, 748

Aristotle, 3, 4, 5, 8, 15, 138, 149, 158, 509, 653, 714, 725, 726

Arizona trees, 121

Arrhenius, Sv., 28, 48, 171

Artemia, 127

Artemis, 561

Ascaris megalocephala, 180, 195

Aschemonella, 255

Assheton, R., 344

Asterina, 342

Asteroides, 423

Asterolampra, 386

Asters, 167, 174

Asthenosoma, 664

Astrorhiza, 255, 463, 587, 607

Astrosclera, 436

Asymmetric substances, 416

Asymmetry, 241

Atrypa, 569

Auerbach, F., 9

Aulacantha, 460

Aulastrum, 471

Aulonia, 468

Auricular height, 93

Autocatalysis, 131

Auximones, 135

Awerinzew, S., 589

Babak, E., 32

Babirussa, teeth of, 634

Baboon, skull of, 771

Bacillus, 39;
B. ramosus, 133

Bacon, Lord, 4, 5, 51, 53, 131, 656, 716

Bacteria, 245, 250

Baer, K. E., von, 3, 55, 57, 155

Balancement, 714, 776

Balfour, F. M., 57, 348

Baltzer, Fr., 327

Bamboo, growth of, 77

Barclay, J., 334

Barfurth, D., 85

Barlow, W., 202

Barratt, J. O. W., 285

Bartholinus, E., 329

Bashforth, Fr., 663

Bast-fibres, strength of, 679

Baster, Job, 138

Bateson, W., 104, 431

Bather, F. A., 578

Batsch, A. J. G. K., 606

Baudrimont, A., and St Ange, 124

Baumann and Roos, 136

Bayliss, W. M., 135, 277

Beads or globules, 234

Beak, shape of, 632

Beal, W. J., 643

Beam, loaded, 674

Bee’s cell, 327, 779

Begonia, 412, 733

Beisa antelope, horns of, 616, 621

Bellerophon, 550

Bénard, H., 259, 319, 448, 590

Bending moments, 19, 677, 696

Beneden, Ed. van, 153, 170, 198

Bergson, H., 7, 103, 251, 611, 721

Bernard, Claude, 2, 13, 127

Bernoulli, James, 580;
John, 30, 54

Berthold, G., 8, 234, 298, 306, 322, 346, 351, 357, 358, 372, 399

Bethe, A., 276

Bialaszewicz, K., 114, 125

Biedermann, W., 431

Bilharzia, egg of, 656

Binuclearity, 286

Biocrystallisation, 454

Biogenetisches Grundgesetz, 608

Biometrics, 78

Bird, flight of, 24;
form of, 673

Bisection of solids, 352, etc.

Bishop, John 31

Bivalve shells, 561

Bjerknes, V. 186

Blackman, F. F. 108, 110, 114, 124, 131, 132

Blackwall, J. 234

Blake, J. F. 536, 547, 553, 578, 583, 728

Blastosphere, 56, 344

Blood-corpuscles, form of, 270;
size of, 36

Blood-vessels, 665

Boas, Fr., 79

Bodo, 230, 269

Boerhaave, Hermann, 380

Bonanni, F., 318

Bone, 425, 435;
repair of, 687;
structure of, 673, 680

Bonnet, Ch., 108, 138, 334, 635

Borelli, J. A., 8, 27, 29, 318, 677, 690

Bosanquet, B., 5

Boscovich, Father R. J., S.J., 8

Bose, J. C., 87

Bostryx, 502

Bottazzi, F., 127

Bottomley, J. T., 135

Boubée, N., 529

Bourgery, J. M., 683

Bourne, G. C., 199

Bourrelet, Plateau’s, 297, 339, 446, 470, 477

Boveri, Th., 38, 147, 170, 198

Bowditch, H. P., 61, 79

Bower, F. O., 406

Bowman, J. H., 428

Boyd, R., 61

Boys, C. V., 233

Brachiopods, 561, 568, 577

Bradford, S. C., 428

Brady, H. B., 255, 606

Brain, growth of, 89;
weight of, 90

Branchipus, 128, 342

Brandt, K., 459, 482

Brauer, A., 180

Braun, A., 636

Bravais, L. and A., 202, 502, 636

Bredig, G., 178

Brewster, Sir D., 209, 337, 350, 431

Bridge, T. W., 671

Bridge construction, 18, 691

Brine shrimps, 127

Brooke, Sir V., 614, 624, 628, 631

Browne, Sir T., 324, 329, 480, 650, 652, 733

Brownian movement, 45, 279, 421

Brücke, C., 160, 199

Buccinum, 520, 527

Buch, Leopold von, 528, 583

Buchner, Hans, 133

Budding, 213, 399

Buffon, on the bee’s cell, 333

Bühle, C. A., 653

Bulimus, 549, 556

Burnet, J., 509

Bütschli, O., 165, 170, 171, 204, 432, 434, 458, 492

Büttel-Reepen, H. von, 332

Byk, A., 419

Cactus, sphaerocrystals, in 434

Cadets, growth of German, 119

Calandrini, G. L., 636

Calcospherites, 421, 434

Callimitra, 472

Callithamnion, spore of, 396

Calman, T. W., 149

Calyptraea, 556

Camel, 703, 704

Campanularia, 237, 262, 747

Campbell, D. H., 302, 397, 402

Camper, P., 742

Camptosaurus, 754

Cannon bone, 730

Cantilever, 678, 694

Cantor, Moritz, 503

Caprella, 743

Caprinella, 567, 577

Carapace of crabs, 744

Cardium, 561

Cariacus, 629

Carlier, E. W., 211

Carnoy, J. B., 468

Carpenter, W. B., 45, 422, 465

Caryokinesis, 14, 157, etc.

Cassini, D., 329

Cassis, 559

Catabolic products, 435

Catalytic action, 130

Catenoid, 218, 223, 227, 252

Causation, 6

Cavolinia, 573

Cayley, A., 385

Celestite, 459

Cell-theory, 197, 199

Cells, forms of, 201;
sizes of, 35

Cellular pathology, 200;
tissue, artificial, 320

Cenosphaera, 470

Centres of force, 156, 196

Centrosome, 167, 168, 173

Cephalopods, 548, etc.;
eggs of, 378

Ceratophyllum, growth of, 97

Ceratorhinus, 612

Cerebratulus, egg of, 189

Cerianthus, 125

Cerithium, 530, 557, 559

Chabrier, J., 25

Chabry, L., 30, 306, 415

Chaetodont fishes, 671, 749

Chaetopterus, egg of, 195

Chamois, horns of, 615

Chapman, Abel, 672

Chara, 303

Characters, biological, 196, 727

Chevron bones, 709

Chick, hatching of, 108

Chilomonas, 114

Chladni figures, 386, 475

Chlorophyll, 291

Choanoflagellates, 253

Chodat, R., 78, 132

Cholesterin, 272

Chondriosomes, 285

Chorinus, 744

Chree, C., 19

Chromatin, 153

Chromidia, 286

Chromosomes, 157, 173, 179, 181, 190, 195

Church, A. H., 639

Cicero, 62

Cicinnus, 502

Cidaris, 664

Circogonia, 479

Cladocarpus, 748

Claparède, E. R, 423

Clathrulina, 470

Clausilia, 520, 549

Claws, 149, 632

Cleland, John, 4

Cleodora, 570–575

Climate and growth, 121

Clio, 570

Close packing, 453

Clytia, 747

Coan, C. A., 514

Coassus, 629

Cod, otoliths of, 432;
skeleton of, 710

Codonella, 248

Codosiga, 253

Coe, W. R., 189

Coefficient of growth, 153;
of temperature, 109

Coelopleurus, 664

Cogan, Dr T., 742

Cohen, A., 110

Cohesion figures, 259

Collar-cells, 253

Colloids, 162, 178, 201, 279, 412, 421, etc.

Collosclerophora, 436

Collosphaera, 459

Colman, S., 514

Comoseris, 327

Compensation, law of, 714, 776

Conchospiral, 531, 539, 594

Conchyliometer, 529

Concretions, 410, etc.

Conjugate curves, 561, 613

Conklin, E. G., 36, 191, 310, 340, 377

Conostats, 427

Continuous girder, 700

Contractile vacuole, 165, 264

Conus, 557, 559, 560

Cook, Sir T. A., 493, 635, 639, 650

Co-ordinates, 723

Corals, 325, 388, 423

Cornevin, Ch., 102

Cornuspira, 594

Correlation, 78, 727

Corystes, 744

Cotton, A., 418

Cox, J., 46

Crane-head, 682

Crayfish, sperm-cells of, 273

Creodonta, 716

Crepidula, 36, 310, 340

Creseis, 570

Cristellaria, 515, 600

Crocodile, 704, 752

Crocus, growth of, 88

Crookes, Sir W., 32

Cryptocleidus, 755

Crystals, 202, 250, 429, 444, 480, 601

Ctenophora, 391

Cube, partition of, 346

Cucumis, growth of, 109

Culmann, Professor C., 682, 697

Cultellus, 564

Curlew, eggs of, 652

Cushman, J. A., 323

Cuvier, 727

Cuvierina, 258, 570

Cyamus, 743

Cyathophyllum, 325, 391

Cyclammina, 595, 596, 602

Cyclas, 561

Cyclostoma, 554

Cylinder, 218, 227, 377

Cymba, 559

Cyme, 502

Cypraea, 547, 554, 560, 561

Cyrtina, 569

Cyrtocerata, 583

Cystoliths, 412

Daday de Dees, E. v., 130

Daffner, Fr., 61, 118

Dalyell, Sir John G., 146

Danilewsky, B., 135

Darling, C. R., 219, 257, 664

D’Arsonval, A., 192, 281

Darwin, C., 4, 44, 57, 332, 431, 465, 549, 624, 671, 714

Dastre, A., 136

Davenport, C. B., 107, 123, 125, 126, 211

De Candolle, A., 108, 643;
A. P., 20;
C., 636

Decapod Crustacea, sperm-cells of, 273

Deer, antlers of, 628

Deformation, 638, 728, etc.

Degree, differences of, 586, 725

Delage, Yves, 153

Delaunay, C. E., 218

Delisle, 31

Dellinger, O. P., 212

Delphinula, 557

Delpino, F., 636

Democritus, 44

Dendy, A., 137, 436, 440, 671

Dentalium, 535, 537, 546, 555, 556, 561

Dentine, 425

Descartes, R., 185, 723

Des Murs, O., 653

Devaux, H., 43

De Vries, H., 108

Diatoms, 214, 386, 426

Diceras, 567

Dickson, Alex., 647

Dictyota, 303, 356, 474

Diet and growth, 134

Difflugia, 463, 466

Diffusion figures, 259, 430

Dimorphism of earwigs, 105

Dimorphodon, 756

Dinenympha, 252

Dinobryon, 248

Dinosaurs, 702, 704, 754

Diodon, 751, 777

Dionaea, 734

Diplodocus, 702, 706, 710

Disc, segmentation of a, 367

Discorbina, 602

Distigma, 246

Distribution, geographical, 457, 606

Ditrupa, 586

Dixon, A. F., 684

Dobell, C. C., 286

Dodecahedron, 336, 478, etc.

Doflein, F. J., 46, 267, 606

Dog’s skull, 773

Dolium, 526, 528, 530, 557, 559, 560

Dolphin, skeleton of, 709

Donaldson, H. H., 82, 93

Dorataspis, 481

D’Orbigny, Alc., 529, 555, 591, 728

Douglass, A. E., 121

Draper, J. W., 165, 264

Dreyer, F. R., 435, 447, 455, 468, 606, 608

Driesch, H., 4, 35, 157, 306, 310, 312, 377, 378, 714

Dromia, 275

Drops, 44, 257, 587

Du Bois-Reymond, Emil, 1, 92

Duerden, J. E., 423

Dufour, Louis, 219

Dujardin, F., 257, 591

Dunan, 7

Duncan, P. Martin, 388

Dupré, Athanase, 279

Durbin, Marion L., 138

Dürer, A., 55, 740, 742

Dutrochet, R. J. H., 212, 624

Dwight, T., 769

Dynamical similarity, 17

Earthworm, calcospheres in, 423

Earwigs, dimorphism in, 104

Ebner, V. von, 444, 683

Echinoderms, larval, 392;
spicules of, 449

Echinus, 377, 378, 664

Eclipse, skeleton of, 739

Ectosarc, 281

Eel, growth of, 85

Efficiency, mechanical, 670

Efficient cause, 6, 158, 248

Eggs of birds, 652

Eiffel tower, 20

Eight cells, grouping of, 381, etc.

Eimer, Th., 606

Einstein formula, 47

Elastic curve, 219, 265, 271

Elaters, 489

Electrical convection, 187;
stimulation of growth, 153

Elephant, 21, 633, 703, 704

Elk, antlers of, 629, 632

Ellipsolithes, 728

Ellis, R. Leslie, 4, 329, 647;
M. M., 147, 656

Elodea, 322

Emarginula, 556

Emmel, V. E., 149

Empedocles, 8

Emperor Moth, 431

Encystment, 213, 283

Engelmann, T. W., 210, 285

Enriques, P., 4, 36, 64, 133, 134, 677

Entelechy, 4, 714

Entosolenia, 449

Enzymes, 135

Epeira, 233

Epicurus, 47

Epidermis, 314, 370

Epilobium, pollen of, 396

Epipolic force, 212

Equatorial plate, 174

Equiangular spiral, 50, 505

Equilibrium, figures of, 227

Equipotential lines, 640

Equisetum, spores of, 290, 489

Errera, Leo, 8, 40, 110, 111, 213, 306, 346, 348, 426

Erythrotrichia, 358, 372, 390

Ethmosphaera, 470

Euastrum, 214

Eucharis, 391

Euclid, 509

Euglena, 376

Euglypha, 189

Euler, L., 3, 208, 385, 484, 690

Eulima, 559

Eunicea, spicules of, 424

Euomphalus, 557, 559

Evelyn, John, 652

Evolution, 549, 610, etc.

Ewart, A. J., 20

Fabre, J. H., 64, 779

Facial angle, 742, 770, 772

Faraday, M., 163, 167, 428, 475

Farmer, J. B. and Digby, 190

Fatigue, molecular, 689

Faucon, A., 88

Favosites, 325

Fechner, G. T., 654, 777

Fedorow, E. S. von, 338

Fehling, H., 76, 126

Ferns, spores of, 396

Fertilisation, 193

Fezzan-worms, 127

Fibonacci, 643

Fibrillenkonus, 285

Fick, R., 57, 683

Fickert, C., 606

Fidler, Prof. T. Claxton, 691, 674, 696

Films, liquid, 215, 217, 426

Filter-passers, 39

Final cause, 3, 248, 714

Fir-cone, 635, 647

Fischel, Alfred, 88

Fischer, Alfred, 40, 172;
Emil, 417, 418;
Otto, 30, 699

Fishes, forms of, 748

Fission, multiplication by, 151

Fissurella, 556

FitzGerald, G. F., 158, 281, 323, 440, 477

Flagellum, 246, 267, 291

Flemming, W., 170, 172, 180

Flight, 24

Flint, Professor, 673

Fluid crystals, 204, 272, 485

Fluted pattern, 260

Fly’s cornea, 324

Fol, Hermann, 168, 194

Folliculina, 249

Foraminifera, 214, 255, 415, 495, 515

Forth Bridge, 694, 699, 700

Fossula, 390

Foster, M., 185

Fraas, E., 716

Frankenheim, M. L., 202

Frazee, O. E., 153

Frédéricq, L., 127, 130

Free cell formation, 396

Friedenthal, H., 64

Frisch, K. von, 671

Frog, egg of, 310, 363, 378, 382;
growth of, 93, 126

Froth or foam, 171, 205, 305, 314, 322, 343

Froude, W., 22

Fucus, 355

Fundulus, 125

Fusulina, 593, 594

Fusus, 527, 557

Gadow, H. F., 628

Galathea, 273

Galen, 3, 465, 656

Galileo, 8, 19, 28, 562, 677, 720

Gallardo, A., 163

Galloway, Principal, 672

Gamble, F. A., 458

Ganglion-cells, size of, 37

Gans, R., 46

Garden of Cyrus, 324, 329

Gastrula, 344

Gauss, K. F., 207, 278, 723

Gebhardt, W., 430, 683

Gelatination, water of, 203

Generating curves and spirals, 526, 561, 615, 637, 641

Geodetics, 440, 488

Geoffroy St Hilaire, Et. de, 714

Geotropism, 211

Gerassimow, J. J., 35

Gerdy, P. N., 491

Geryon, 744

Gestaltungskraft, 485

Giard, A., 156

Gilmore, C. W., 707

Giraffe, 705, 730, 738

Girardia, 321, 408

Glaisher, J., 250

Glassblowing, 238, 737

Gley, E., 135, 136

Globigerina, 214, 234, 440, 495, 589, 602, 604, 606

Gnomon, 509, 515, 591

Goat, horns of, 613

Goat moth, wings of, 430

Goebel, K., 321, 397, 408

Goethe, 20, 38, 199, 714, 719

Golden Mean, 511, 643, 649

Goldschmidt, R., 286

Goniatites, 550, 728

Gonothyraea, 747

Goodsir, John, 156, 196, 580

Gottlieb, H., 699

Gourd, form of, 737

Grabau, A. H., 531, 539, 550

Graham, Thomas, 162, 201, 203

Grant, Kerr, 259

Grantia, 445

Graphic statics, 682

Gravitation, 12, 32

Gray, J., 188

Greenhill, Sir A. G., 19

Gregory, D. F., 330, 675

Greville, R. K., 386

Gromia, 234, 257

Gruber, A., 165

Gryphaea, 546, 576, 577

Guard-cells, 394

Gudernatsch, J. F., 136

Guillemot, egg of, 652

Gulliver, G., 36

Günther, F. C., 633, 654

Gurwitsch, A., 285

Häcker, V., 458

Haddock, 774

Haeckel, E., 199, 445, 454, 455, 457, 467, 480, 481

Hair, pigmentation of, 430

Hales, Stephen, 36, 59, 95, 669

Haliotis, 514, 527, 546, 547, 554, 555, 557, 561

Hall, C. E., 119

Haller, A. von, 2, 54, 56, 59, 64, 68

Hardesty, Irving, 37

Hardy, W. B., 160, 162, 172, 187, 287

Harlé, N., 28

Harmozones, 135

Harpa, 526, 528, 559

Harper, R. A., 283

Harpinia, 746

Harting, P., 282, 420, 426, 434

Hartog, M., 163, 327

Harvey, E. N. and H. W., 187

Hatai, S., 132, 135

Hatchett, C., 420

Hatschek, B., 180

Haughton, Rev. S., 334, 666

Haüy, R. J., 720

Hay, O. P., 707

Haycraft, J. B., 211, 690

Head, length of, 93

Heart, growth of, 89;
muscles of, 490

Heath, Sir T., 511

Hegel, G. W. F., 4

Hegler, 680, 688

Heidenhain, M., 170, 212

Heilmann, Gerhard, 757, 768, 772

Helicoid, 230;
cyme, 502, 605

Helicometer, 529

Helicostyla, 557

Heliolites, 326

Heliozoa, 264, 460

Helix, 528, 557

Helmholtz, H. von, 2, 9, 25

Henderson, W. P., 323

Henslow, G., 636

Heredity, 158, 286, 715

Hermann, F., 170

Hero of Alexandria, 509

Heron-Allen, E., 257, 415, 465

Herpetomonas, 268

Hertwig, O., 56, 114, 153, 199, 310;
R., 170, 285

Hertzog, R. O., 109

Hess, W., 666, 668

Heteronymous horns, 619

Heterophyllia, 388

Hexactinellids, 429, 452, 453

Hexagonal symmetry, 319, 323, 471, 513

Hickson, S. J., 424

Hippopus, 561

His, W., 55, 56, 74, 75

Hobbes, Thomas, 159

Höber, R., 1, 126, 130, 172

Hodograph, 516

Hoffmann, C., 628

Hofmeister, F., 41; W., 87, 210, 234, 304, 306, 636, 639

Holland, W. J., 707

Holmes, O. W., 62, 737

Holothuroid spicules, 440, 451

Homonymous horns, 619

Homoplasy, 251

Hooke, Robert, 205

Hop, growth of, 118;
stem of, 627

Horace, 44

Hormones, 135

Horns, 612

Horse, 694, 701, 703, 764

Houssay, F., 21

Huber, P., 332

Huia bird, 633

Humboldt, A. von, 127

Hume, David, 6

Hunter, John, 667, 669, 713, 715

Huxley, T. H., 423, 722, 752

Hyacinth, 322, 394

Hyalaea, 571–577

Hyalonema, 442

Hyatt, A., 548

Hyde, Ida H., 125, 163, 184, 188

Hydra, 252;
egg of, 164

Hydractinia, 342

Hydraulics, 669

Hydrocharis, 234

Hyperia, 746

Hyrachyus, 760, 765

Hyracotherium, 766, 768

Ibex, 617

Ice, structure of, 428

Ichthyosaurus, 755

Icosahedron, 478

Iguanodon, 706, 708

Inachus, sperm-cells of, 273

Infusoria, 246, 489

Intussusception, 202

Inulin, 432

Invagination, 56, 344

Iodine, 136

Irvine, Robert, 414, 434

Isocardia, 561, 577

Isoperimetrical problems, 208, 346

Isotonic solutions, 130, 274

Iterson, G. van, 595

Jackson, C. M., 75, 88, 106

Jamin, J. C., 418

Janet, Paul, 5, 18, 673

Japp, F. R., 417

Jellett, J. H., 1

Jenkin, C. F., 444

Jenkinson, J. W., 94, 114, 170

Jennings, H. S., 212, 492;
Vaughan, 424

Jensen, P., 211

Johnson, Dr S., 62

Joly, John, 9, 63

Jost, L., 110, 111

Juncus, pith of, 335

Jungermannia, 404

Kangaroo, 705, 706, 709

Kanitz, Al., 109

Kant, Immanuel, 1, 3, 714

Kappers, C. U. A., 566

Kellicott, W. E., 91

Kelvin, Lord, 9, 49, 188, 202, 336, 453

Kepler, 328, 480, 486, 643, 650

Kienitz-Gerloff, F., 404, 408

Kirby and Spence, 28, 30, 127

Kirchner, A., 683

Kirkpatrick, R., 437

Klebs, G., 306

Kny, L., 680

Koch, G. von, 423

Koenig, Samuel, 330

Kofoid, C. A., 268

Kölliker, A. von, 413

Kollmann, M., 170

Koltzoff, N. K., 273, 462

Koninckina, 570

Koodoo, horns of, 624

Köppen, Wladimir, 111

Korotneff, A., 377

Kraus, G., 77

Krogh, A., 109

Krohl, 666

Kühne, W., 235

Küster, E., 430

Lafresnaye, F. de, 653

Lagena, 251, 256, 260, 587

Lagrange, J. L., 649

Lalanne, L., 334

Lamarck, J. B. de, 549, 716

Lamb, A. B., 186

Lamellaria, 554

Lamellibranchs, 561

Lami, B., 296, 643

Laminaria, 315

Lammel, R., 100

Lanchester, F. W., 26

Lang, Arnold, 561

Lankester, Sir E. Ray, 4, 251, 348, 465

Laplace, P. S. de, 1, 207, 217

Larmor, Sir J., 9, 259

Lavater, J. C., 740

Law, Borelli’s, 29;
Brandt’s, 482;
of Constant Angle, 599;
Errera’s, 213, 306;
Froude’s, 22;
Lamarle’s, 309;
of Mass, 130;
Maupertuis’s, 208;
Müller’s, 481;
of Optimum, 110;
van’t Hoff’s, 109;
Willard-Gibbs’, 280;
Wolff’s, 3, 51, 155

Leaping, 29

Leaves, arrangement of, 635;
form of, 731

Ledingham, J. C. G., 211

Leduc, Stéphane, 162, 167, 185, 219, 259, 415, 428, 431, 590

Leeuwenhoek, A. van, 36, 209

Leger, L., 452

Le Hello, P., 30

Lehmann, O., 203, 272, 440, 485, 590

Leibniz, G. W. von, 3, 5, 159, 385

Leidenfrost, J. G., 279

Leidy, J., 252, 468

Leiper, R. T., 660

Leitch, I., 112

Leitgeb, H., 305

Length-weight coefficient, 98–103, 775

Leonardo da Vinci, 27, 635;
of Pisa, 643

Lepeschkin, 625

Leptocephalus, 87

Leray, Ad., 18

Lesage, G. L., 18

Leslie, Sir John, 163, 503

Lestiboudois, T., 636

Leucocytes, 211

Levers, Orders of, 690

Levi, G., 35, 37

Lewis, C. M., 280

Lhuilier, S. A. J., 330

Liesegang’s rings, 427, 475

Light, pressure of, 48

Lillie, F. R., 4, 147, 341;
R. S., 180, 187, 192

Lima, 565

Limacina, 571

Lines of force, 163;
of growth, 562

Lingula, 251, 567

Linnaeus, 28, 250, 547, 720

Lion, brain of, 91

Liquid veins, 265

Lister, Martin, 318;
J. J., 436

Listing, J. B., 385

Lithostrotion, 325

Littorina, 524

Lituites, 546, 550

Llama, 703

Lobsters’ claws, 149

Locke, John, 6

Loeb, J., 125, 132, 135, 136, 147, 157, 191, 193

Loewy, A., 281

Logarithmic spiral, 493, etc.

Loisel, G., 88

Loligo, shell of, 575

Lo Monaco, 83

Lönnberg, E., 614, 632

Looss, A., 660

Lotze, R. H., 55

Love, A. E. H., 674

Lucas, F. A., 138

Luciani, L., 83

Lucretius, 47, 71, 137, 160

Ludwig, Carl, 2;
F., 643;
H. J., 342

Lupa, 744

Lupinus, growth of, 109, 112

Macalister, A., 557

MacAlister, Sir D., 673, 683

Macallum, A. B., 277, 287, 357, 395;
J. B., 492

McCoy, F., 388

Mach, Ernst, 209, 330

Machaerodus, teeth of, 633

McKendrick, J. G., 42

McKenzie, A., 418

Mackinnon, D. L., 268

Maclaurin, Colin, 330, 779

Macroscaphites, 550

Mactra, 562

Magnitude, 16

Maillard, L., 163

Maize, growth of, 109, 111, 298

Mall, F. P., 492

Maltaux, Mlle, 114

Mammoth, 634, 705

Man, growth of, 61;
skull of, 770

Maraldi, J. P., 329, 473

Marbled papers, 736

Marcus Aurelius, 609

Markhor, horns of, 619

Marsh, O. C., 706, 754

Marsigli, Comte L. F. de, 652

Massart, J., 114

Mastodon, 634

Mathematics, 719, 778, etc.

Mathews, A., 285

Matrix, 656

Matter and energy, 11

Matthew, W. D., 707

Matuta, 744

Maupas, M., 133

Maupertuis, 3, 5, 208

Maxwell, J. Clerk, 9, 18, 40, 44, 160, 207, 385, 691

Mechanical efficiency, 670

Mechanism, 5, 161, 185, etc.

Meek, C. F. U., 190

Melanchthon, 4

Melanopsis, 557

Meldola, R., 670

Melipona, 332

Mellor, J. W., 134

Melo, 525

Melobesia, 412

Melsens, L. H. F., 282

Membrane-formation, 281

Mensbrugghe, G. van der, 212, 298, 470

Meserer, O., 683

Mesocarpus, 289

Mesohippus, 766

Metamorphosis, 82

Meves, F., 163, 285

Meyer, Arthur, 432;
G. H., 8, 682, 683

Micellae, 157

Michaelis, L., 277

Microchemistry, 288

Micrococci, 39, 245, 250

Micromonas, 38

Miliolidae, 595, 604

Milner, R. S., 280

Milton, John, 779

Mimicry, 671

Minchin, E. A., 267, 444, 449, 455

Minimal areas, 208, 215, 225, 293, 306, 336, 349

Minot, C. S., 37, 72, 722

Miohippus, 767

Mitchell, P. Chalmers, 703

Mitosis, 170

Mitra, 557, 559

Möbius, K., 449

Modiola, 562

Mohl, H. von, 624

Molar and molecular forces, 53

Mole-cricket, chromosomes of, 181

Molecular asymmetry, 416

Molecules, 41

Möller, V. von, 593

Monnier, A., 78, 132

Monticulipora, 326

Moore, B., 272

Morey, S., 264

Morgan, T. H., 126, 134, 138, 147

Morita, 699

Morphodynamique, 156

Morphologie synthétique, 420

Morphology, 719, etc.

Morse, Max, 136

Moseley, H., 8, 518, 521, 538, 553, 555, 592

Moss, embryo of, 374;
gemma of, 403;
rhizoids of, 356

Mouillard, L. P., 27

Mouse, growth of, 82

Mucor, sporangium of, 303

Müllenhof, K. von, 25, 332

Müller, Fritz, 3;
Johannes, 459, 481

Mummery, J. H., 425

Munro, H., 323

Musk-ox, horns of, 615

Mya, 422, 561

Myonemes, 562

Naber, H. A., 511, 650

Nägeli, C., 124, 159, 210

Nassellaria, 472

Natica, 554, 557, 559

Natural selection, 4, 58, 137, 456, 586, 609, 651, 653

Naumann, C. F., 529, 531, 539, 550, 577, 594, 636;
J. F., 653

Nautilus, 355, 494, 501, 515, 518, 532, 535, 546, 552, 557, 575, 577,
580, 592, 633;
hood of, 554;
kidney of, 425;
N. umbilicatus, 542, 547, 554

Nebenkern, 285

Neottia, pollen of, 396

Nereis, egg of, 342, 378, 453

Nerita, 522, 555

Neumayr, M., 608

Neutral zone, 674, 676, 686

Newton, 1, 6, 158, 643, 721

Nicholson, H. A., 325, 327

Noctiluca, 246

Nodoid, 218, 223

Nodosaria, 262, 535, 604

Norman, A. M., 465

Norris, Richard, 272

Nostoc, 300, 313

Notosuchus, 753

Nuclear spindle, 170;
structure, 166

Nummulites, 504, 552, 591

Nussbaum, M., 198

Oekotraustes, 550

Ogilvie-Gordon, M. M., 423

Oil-globules, Plateau’s, 219

Oithona, 742

Oken, L., 4, 635

Oliva, 554

Ootype, 660

Operculina, 594

Operculum of gastropods, 521

Oppel, A., 88

Optimum temperature, 110

Orbitolites, 605

Orbulina, 59, 225, 257, 587, 598, 604, 607

Organs, growth of, 88

Orthagoriscus, 751, 775, 777

Orthis, 561, 567

Orthoceras, 515, 548, 551, 556, 579, 735

Orthogenesis, 549

Orthogonal trajectories, 305, 377, 400, 640, 678

Orthostichies, 649

Orthotoluidene, 219

Oryx, horns of, 616

Osborn, H. F., 714, 727, 760

Oscillatoria, 300

Osmosis, 124, 287, etc.

Osmunda, 396, 406

Ostrea, 562

Ostrich, 25, 707, 708

Ostwald, Wilhelm, 44, 131, 426;
Wolfgang, 32, 77, 82, 132, 277, 281

Otoliths, 425, 432

Ovis Ammon, 614

Owen, Sir R., 20, 575, 654, 669, 715

Ox, cannon-bone of, 730, 738;
growth of, 102

Oxalate, calcium, 412, 434

Palaeechinus, 663

Palm, 624

Pander, C. H., 55

Pangenesis, 44, 157

Papillon, Fernand, 10

Pappus of Alexandria, 328

Parabolic girder, 693, 696

Parahippus, 767

Paralomis, 744

Paraphyses of mosses, 351

Parastichies, 640, 641

Passiflora, pollen of, 396

Pasteur, L., 416

Patella, 561

Pauli, W., 211, 434

Pearl, Raymond, 90, 97, 654

Pearls, 425, 431

Pearson, Karl, 36, 78

Peas, growth of, 112

Pecten, 562

Peddie, W., 182, 272, 344, 448

Pellia, spore of, 302

Pelseneer, P., 570

Pendulum, 30

Peneroplis, 606

Percentage-curves, Minot’s, 72

Pericline, 360

Periploca, pollen of, 396

Peristome, 239

Permeability, magnetic, 177, 182

Perrin, J., 43, 46

Peter, Karl, 117

Pettigrew, J. B., 490

Pfeffer, W., 111, 273, 688

Pflüger, E., 680

Phagocytosis, 211

Phascum, 408

Phase of curve, 68, 81, etc.

Phasianella, 557, 559

Phatnaspis, 482

Phillipsastraea, 327

Philolaus, 779

Pholas, 561

Phormosoma, 664

Phractaspis, 484

Phyllotaxis, 635

Phylogeny, 196, 251, 548, 716

Pike, F. H., 110

Pileopsis, 555

Pinacoceras, 584

Pithecanthropus, 772

Pith of rush, 335

Plaice, 98, 105, 117, 432, 710, 774

Planorbis, 539, 547, 554, 557, 559

Plateau, F., 30, 232;
J. A. F., 192, 212, 218, 239, 275, 297, 374, 477

Plato, 2, 478, 720;
Platonic bodies, 478

Plesiosaurs, 755

Pleurocarpus, 289

Pleuropus, 573

Pleurotomaria, 557

Plumulariidae, 747

Pluteus larva, 392, 415

Podocoryne, 342

Poincaré, H., 134

Poiseuille, J. L. M., 669

Polar bodies, 179;
furrow, 310, 340

Polarised light, 418

Polarity, morphological, 166, 168, 246, 295, 284

Pollen, 396, 399

Polyhalite, 433

Polyprion, 749, 776

Polyspermy, 193

Polytrichum, 355

Pomacanthus, 749

Popoff, M., 286

Potamides, 554

Potassium, in living cells, 288

Potential energy, 208, 294, 601, etc.

Potter’s wheel, 238

Potts, R., 126

Pouchet, G., 415

Poulton, E. B., 670

Poynting, J. H., 235

Precocious segregation, 348

Preformation, 54, 159

Prenant, A., 163, 104, 189, 286, 289

Prévost, Pierre, 18

Pringsheim, N., 377

Probabilities, theory of, 61

Productus, 567

Protective colouration, 671

Protococcus, 59, 300, 410

Protoconch, 531

Protohippus, 767

Protoplasm, structure of, 172

Przibram, Hans, 16, 82, 107, 149, 204, 211, 418, 595;
Karl, 46

Psammobia, 564

Pseuopriacauthus, 749

Pteranodon, 756

Pteris, antheridia of, 409

Pteropods of, 258, 570

Pulvinulina, 514, 595, 600, 602

Pupa, 530, 549, 556

Pütter, A., 110, 211, 492

Pyrosoma, egg of, 377

Pythagoras, 2, 509, 651, 720, 779

Quadrant, bisection of, 359

Quekett, J. T., 423

Quetelet, A., 61, 78, 93

Quincke, G. H., 187, 191, 279, 421

Rabbit, skull of, 764

Rabl, K., 36, 310

Radial co-ordinates, 730

Radiolaria, 252, 264, 457, 467, 588, 607

Rainey, George, 7, 420, 431, 434

Rainfall and growth, 121

Ram, horns of, 613–624

Ramsden, W., 282

Ramulina, 255

Rankine, W. J. Macquorn, 697, 712

Ransom’s waves, 164

Raphides, 412, 429, 434

Raphidiophrys, 460, 463

Rasumowsky, 683

Rat, growth of, 106

Rath, O. vom, 181

Rauber, A., 200, 305, 310, 380, 382, 398, 677, 683

Ray, John, 3

Rayleigh, Lord, 43, 44

Réaumur, R. A. de, 8, 108, 329

Reciprocal diagrams, 697

Rees, R. van, 374

Regeneration, 138

Reid, E. Waymouth, 272

Reinecke, J. C. M., 528

Reinke, J., 303, 305, 355, 356

Reniform shape, 735

Reticularia, 569

Reticulated patterns, 258

Réticulum plasmatique, 468

Rhabdammina, 589

Rheophax, 263

Rhinoceros, 612, 760

Rhumbler, L., 162, 165, 260, 322, 344, 465, 466, 589, 590, 595, 599,
608, 628

Rhynchonella, 561

Riccia, 372, 403, 405

Rice, J., 242, 273

Richardson, G. M., 416

Riefstahl, E., 578

Riemann, B., 385

Ripples, 33, 261, 323

Rivularia, 300

Roaf, H. C., 272

Robert, A., 306, 339, 348, 377

Roberts, C., 61

Robertson, T. B., 82, 132, 191, 192

Robinson, A., 681

Rörig, A., 628

Rose, Gustav, 421

Rossbach, M. J., 165

Rotalia, 214, 535, 602

Rotifera, cells of, 38

Roulettes, 218

Roux, W., 8, 55, 57, 157, 194, 378, 383, 666, 683

Ruled surfaces, 230, 270, 582

Ruskin, John, 20

Russow, ——, 73, 75

Ryder, J. A., 376

Sachs, J., 35, 38, 95, 108, 110, 111, 200, 360, 398, 399, 624, 635,
640, 651, 680

Sachs’s rule, 297, 300, 305, 347, 376

Saddles, of ammonites, 583

Sagrina, 263

St Venant, Barré de, 621, 627

Salamander, sperm-cells of, 179

Salpingoeca, 248

Salt, crystals of, 429

Salvinia, 377

Samec, M., 434

Samter, M. and Heymons, 130

Sandberger, G., 539

Sapphirina, 742

Saville Kent, W., 246, 247, 248

Scalaria, 526, 547, 554, 557, 559

Scale, effect of, 17, 438

Scaphites, 550

Scapula, human, 769

Scarus, 749

Schacko, G., 604

Schaper, A. A., 83

Schaudinn, F., 46, 286

Scheerenumkehr, 149

Schewiakoff, W., 189, 462

Schimper, C. F., 502, 636

Schmaltz, A., 675

Schmankewitsch, W., 130

Schmidt, Johann, 85, 87, 118

Schönflies, A., 202

Schultze, F. E., 452, 454

Schwalbe, G., 666

Schwann, Theodor, 199, 380, 591

Schwartz, Fr., 172

Schwendener, S., 210, 305, 636, 678

Scorpaena, 749

Scorpioid cyme, 502

Scott, E. L., 110;
W. B., 768

Scyromathia, 744

Searle, H., 491

Sea urchins, 661;
egg of, 173;
growth of, 117, 147

Sebastes, 749

Sectio aurea, 511, 643, 649

Sedgwick, A., 197, 199

Sédillot, Charles E., 688

Segmentation of egg, 57, 310, 344, 382, etc.;
spiral do., 371, 453

Segner, J. A. von, 205

Selaginella, 404

Semi-permeable membranes, 272

Sepia, 575, 577

Septa, 577, 592

Serpula, 603

Sexual characters, 135

Sharpe, D., 728

Shearing stress, 684, 730, etc.

Sheep, 613, 730, 738

Shell, formation of, 422

Sigaretus, 554

Silkworm, growth of, 83

Similitude, principle of, 17

Sims Woodhead, G., 414, 434

Siphonogorgia, 413

Skeleton, 19, 438, 675, 691, etc.

Snow crystals, 250, 480, 611

Soap-bubbles, 43, 219, 299, 307, etc.

Socrates, 8

Sohncke, L. A., 202

Solanum, 625

Solarium, 547, 554, 557, 559

Solecurtus, 564

Solen, 565

Sollas, W. J., 440, 450, 455

Solubility of salts, 434

Sorby, H. C., 412, 414, 728

Spallanzani, L., 138

Span of arms, 63, 93

Spangenberg, Fr., 342

Specific characters, 246, 380;
inductive capacity, 177;
surface, 32, 215

Spencer, Herbert, 18, 22

Spermatozoon, path of, 193

Sperm-cells of Crustacea, 273

Sphacelaria, 351

Sphaerechinus, 117, 147

Sphagnum, 402, 407

Sphere, 218, 225

Spherocrystals, 434

Spherulites, 422

Spicules, 282, 411, etc.

Spider’s web, 231

Spindle, nuclear, 169, 174

Spinning of protoplasm, 164

Spiral, geodetic, 488;
logarithmic, 493, etc.;
segmentation, 371, 453

Spireme, 173, 180

Spirifer, 561, 568

Spirillum, 46, 253

Spirochaetes, 46, 230, 266

Spirographis, 586

Spirogyra, 12, 221, 227, 242, 244, 275, 287, 289

Spirorbis, 586, 603

Spirula, 528, 547, 554, 575, 577

Spitzka, E. A., 92

Splashes, 235, 236, 254, 260

Sponge-spicules, 436, 440

Spontaneous generation, 420

Sporangium, 406

Spottiswoode, W., 779

Spray, 236

Stallo, J. B., 1

Standard deviation, 78

Starch, 432

Starling, E. H., 135

Stassfurt salt, 433

Stegocephalus, 746

Stegosaurus, 706, 707, 710, 754

Steiner, Jacob, 654

Steinmann, G., 431

Stellate cells, 335

Stentor, 147

Stereometry, 417

Sternoptyx, 748

Stillmann, J. D. B., 695

St Loup, R., 82

Stokes, Sir G. G., 44

Stolc, Ant., 452

Stomach, muscles of, 490

Stomata, 393

Stomatella, 554

Strasbürger, E., 35, 283, 409

Straus-Dürckheim, H. E., 30

Stream-lines, 250, 673, 736

Strength of materials, 676, 679

Streptoplasma, 391

Strophomena, 567

Studer, T., 413

Stylonichia, 133

Succinea, 556

Sunflower, 494, 635, 639, 688

Surface energy, 32, 34, 191, 207, 278, 293, 460, 599

Survival of species, 251

Sutures of cephalopods, 583

Swammerdam, J., 8, 87, 380, 528, 585

Swezy, Olive, 268

Sylvester, J. J., 723

Symmetry, meaning of, 209

Synapta, egg of, 453

Syncytium, 200

Synhelia, 327

Szielasko, A., 654

Tadpole, growth of, 83, 114, 138, 153

Tait, P. G., 35, 43, 207, 644

Taonia, 355, 356

Tapetum, 407

Tapir, 741, 763

Taylor, W. W., 277, 282, 426, 428

Teeth, 424, 612, 632

Telescopium, 557

Telesius, Bernardinus, 656

Tellina, 562

Temperature coefficient, 109

Terebra, 529, 557, 559

Terebratula, 568, 574, 576

Teredo, 414

Terni, T., 35

Terquem, O., 329

Tesch, J. J., 573

Tetractinellida, 443, 450

Tetrahedral symmetry, 315, 396, 476

Tetrakaidecahedron, 337

Tetraspores, 396

Textularia, 604

Thamnastraea, 327

Thayer, J. E., 672

Thecidium, 570

Thecosmilia, 325

Théel, H., 451

Thienemann, F. A. L., 653

Thistle, capitulum of, 639

Thoma, R., 666

Thomson, James, 18, 259;
J. A., 465;
J. J., 235, 280;
Wyville, 466

Thurammina, 256

Thyroid gland, 136

Time-element, 51, 496, etc.;
time-energy diagram, 63

Tintinnus, 248

Tissues, forms of, 293

Titanotherium, 704, 762

Tomistoma, 753

Tomlinson, C., 259, 428

Tornier, G., 707

Torsion, 621, 624

Trachelophyllum, 249

Transformations, theory of, 562, 719

Traube, M., 287

Trees, growth of, 119;
height of, 19

Trembley, Abraham, 138, 146

Treutlein, P., 510

Trianea, hairs of, 234

Triangle, properties of, 508;
of forces, 295

Triasters, 327

Trichodina, 252

Trichomastix, 267

Triepel, H., 683, 684

Triloculina, 595

Triton, 554

Trochus, 377, 557, 560;
embryology of, 340

Tröndle, A., 625

Trophon, 526

Trout, growth of, 94

Trypanosomes, 245, 266, 269

Tubularia, 125, 126, 146

Turbinate shells, 534

Turbo, 518, 555

Turgor, 125

Turner, Sir W., 769

Turritella, 489, 524, 527, 555, 557, 559

Tusks, 515, 612

Tutton, A. E. H., 202

Twining plants, 624

Tyndall, John, 428

Umbilicus of shell, 547

Underfeeding, effect of, 106

Undulatory membrane, 266

Unduloid, 218, 222, 229, 246, 256

Unio, 341

Univalve shells, 553

Urechinus, 664

Vaginicola, 248

Vallisneri, Ant., 138

Van Iterson, G., 595

Van Rees, R., 374

Van’t Hoff, J. H., 1, 110, 433

Variability, 78, 103

Venation of wings, 385

Verhaeren, Emile, 778

Verworn, M., 198, 211, 467, 605

Vesque, J., 412

Vierordt, K., 73

Villi, 32

Vincent, J. H., 323

Vines, S. H., 502

Virchow, R., 200, 286

Vital phenomena, 14, 417, etc.

Vitruvius, 740

Volkmann, A. W., 669

Voltaire, 4, 146

Vorticella, 237, 246, 291

Wager, H. W. T., 259

Walking, 30

Wallace, A. R., 5, 432, 549

Wallich-Martius, 77

Warburg, O., 161

Warburton, C., 233

Ward, H. Marshall, 133

Warnecke, P., 93

Watase, S., 378

Water, in growth, 125

Watson, F. R., 323

Weber, E. H., 210, 259, 669;
E. H. and W. E., 30;
Max, 91

Weight, curve of, 64, etc.

Weismann, A., 158

Werner, A. G., 19

Wettstein, R. von, 728

Whale, affinities, 716;
size, 21;
structure, 708

Whipple, I. L., 123

Whitman, C. O., 157, 164, 193, 194, 199, 200

Whitworth, W. A., 506, 512

Wiener, A. F., 45

Wildeman, E. de, 307, 355

Willey, A., 425, 548, 555, 578

Williamson, W. C., 423, 609

Willughby, Fr., 318

Wilson, E. B., 150, 163, 173, 195, 199, 311, 341, 342, 398, 453

Winge, O., 433

Winter eggs, 283

Wissler, Clark, 79

Wissner, J., 636

Wöhler, Fr., 416, 420

Wolff, J., 683;
J. C. F., 3, 51, 155

Wood, R. W., 590

Woods, R. H., 666

Woodward, H., 578;
S. P., 554, 567

Worthington, A. M., 235, 254

Wreszneowski, A., 249

Wright, Chauncey, 335

Wright, T. Strethill, 210

Wyman, Jeffrey, 335

Yeast cell, 213, 242

Yield-point, 679

Yolk of egg, 165, 660

Young, Thomas, 9, 36, 669, 691

Zangger, H., 282

Zeising, A., 636, 650

Zeleny, C., 149

Zeuglodon, 716

Zeuthen, H. G., 511

Ziehen, Ch., 92

Zittel, K. A. von, 325, 327, 548, 584

Zoogloea, 282

Zschokke, F., 683

Zsigmondy, 39

Zuelzer, M., 165

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