53. Annular chromosomes of mole-cricket (Wilson, after vom Rath) . . . 181 54–56. Diagrams illustrating a hypothetic field of force in caryokinesis (Prof. W. Peddie) . . . 182–4 57. An artificial figure of caryokinesis (Leduc) . . . 186 58. A segmented egg of _Cerebratulus_ (Prenant, after Coe) . . . 189 59. Diagram of a field of force with two like poles . . . 189 60. A budding yeast-cell . . . 213 61. The roulettes of the conic sections . . . 218 62. Mode of development of an unduloid from a cylindrical tube . . . 220 63–65. Cylindrical, unduloid, nodoid and catenoid oil-globules (Plateau) . . . 222, 3 66. Diagram of the nodoid, or elastic curve . . . 224 67. Diagram of a cylinder capped by the corresponding portion of a sphere . . . 226 68. A liquid cylinder breaking up into spheres . . . 227 69. The same phenomenon in a protoplasmic cell of _Trianea_ . . . 234 70. Some phases of a splash (A. M. Worthington) . . . 235 71. A breaking wave (_do._) . . . 236 72. The calycles of some campanularian zoophytes . . . 237 73. A flagellate monad, _Distigma proteus_ (Saville Kent) . . . 246 74. _Noctiluca miliaris_, diagrammatic . . . 246 75. Various species of _Vorticella_ (Saville Kent and others) . . . 247 76. Various species of _Salpingoeca_ (_do._) . . . 248 77. Species of _Tintinnus_, _Dinobryon_ and _Codonella_ (_do._) . . . 248 78. The tube or cup of _Vaginicola_ . . . 248 79. The same of _Folliculina_ . . . 249 80. _Trachelophyllum_ (Wreszniowski) . . . 249 81. _Trichodina pediculus_ . . . 252 82. _Dinenymplia gracilis_ (Leidy) . . . 253 83. A “collar-cell” of _Codosiga_ . . . 254 84. Various species of _Lagena_ (Brady) . . . 256 85. Hanging drops, to illustrate the unduloid form (C. R. Darling) . . . 257 86. Diagram of a fluted cylinder . . . 260 87. _Nodosaria scalaris_ (Brady) . . . 262 88. Fluted and pleated gonangia of certain Campanularians (Allman) . . . 262 89. Various species of _Nodosaria_, _Sagrina_ and _Rheophax_ (Brady) . . . 263 90. _Trypanosoma tineae_ and _Spirochaeta anodontae_, to shew undulating membranes (Minchin and Fantham) . . . 266 91. Some species of _Trichomastix_ and _Trichomonas_ (Kofoid) . . . 267 92. _Herpetomonas_ assuming the undulatory membrane of a Trypanosome (D. L. Mackinnon) . . . 268 93. Diagram of a human blood-corpuscle . . . 271 94. Sperm-cells of decapod crustacea, _Inachus_ and _Galathea_ (Koltzoff) . . . 273 95. The same, in saline solutions of varying density (_do._) . . . 274 96. A sperm-cell of _Dromia_ (_do._) . . . 275 97. Chondriosomes in cells of kidney and pancreas (Barratt and Mathews) . . . 285 98. Adsorptive concentration of potassium salts in various plant-cells (Macallum) . . . 290 99–101. Equilibrium of surface-tension in a floating drop . . . 294, 5 102. Plateau’s “bourrelet” in plant-cells; diagrammatic (Berthold) . . . 298