LIST OF ILLUSTRATIONS xv 



PIQUKE p^gj, 



38. A fragment of a Lichen I73 



39. A fragment of a Silver Poplar root . 176 



40. Potentilla verna Igl 



41. Flower of Meadow Sage 183 



42. Alpine Lousewort {Pedicularis asplenifolia) 184 



43. Flower of Birthwort (J WstoZocfcia cZemaito's) 185 



44. Alpine Butterwort {Pinguicula alpina) 185 



45. Daphne mezereum and Daphne stnata 187 



46. Common Orcliis (Orchis mascula) . . 188 



47. Head of a Butterfly 190 



48. Mouth-parts of the Cocfaoacli 191 



49. Head of the Bee 192 



50. Flowers of the Willow 194 



51. The Yucca-moth (P;-o«2(6a !/MccaseMa) 201 



52. The fertilization of the Yucca 202 



53. Scent-scales of diurnal Butterflies 217 



54. A portion of the upper surface of the wing of a male ' blue ' {Lyccena 



menalcas) 218 



55. Zeuxidia ivallacel, male ......... 218 



56. Leptodofa hyalina ........... 224 



57. Moina paradoxa, male 225 



58. Moina paradoxa, female ......... 226 



59. An Amoeba: the process of division 253 



60. Stentor rceselii, trumpet-animalcule 254 



61. Holophrya multifiliis . . . . . . . . . . 256 



62. Pandorina morum ........... 257 



63. Volwx aureus 270 



64. Fucus platycarpus, brown sea-wrack ....... 272 



65. Copulation in a Daphnid (Lyncaeid) 276 



66. Spermatozoa of various Daphnids 277 



67. Spermatozoa of various animals 278 



68. Diagram of a spermatozoon 279, 338 



69. Ovum of the Sea-urchin 281, 338 



70. Daphnella 283 



71. Bythotrephes longimanus 283 



72. Sida crystalUna, a Daphnid 284 



73. Diagi'ammatic longitudinal section of a hen's egg before incubation . 285 



74. Diagram of nuclear division 288 



75. Process of fertilization in Ascaris megaloeephala . . . . . 296 



76. Diagram of the maturation divisions of the ovum .... 299 

 y;. Diagram of the maturation divisions of the sperm-cell . . . 301 

 78! Diagram of the maturation of a parthenogenetic ovum . . . 305 



79. The two maturation divisions of the ' drone eggs ' of the Bee . 307, 337 



80. Fertilization of the ovum of a Gasteropod 310 



81. Formation of polar bodies in a Lichen 313 



82. Fertilization in the Lily 314 



83. Conjugation of Noctiluca 317 



84. Conjugation and polar body formation in the Sun-animalcule . . 319 



