XIV LIST OF ILLUSTRATIONS 



FIG. 



32. Diagram of a typical spermatozoon 



33. Forms of spermatozoa (not drawn to scale) 



34. Diagram of maturation and fertilisation. (From " Evolution 



of Sex ") . 



35. Oogenesis and spermatogenesis — after Boveri . 



36. Fertilisation of egg-cell — after Fol 



37. Diagram showing relative size of an egg-cell and a sperm-cell 



38. Fertilisation in Ascaris megalocephala — after Boveri . 



39. Modes of Segmentation ..... 



40. Life-history of a coral, Monoxenia darwinii — from Haeckel 



41. Embryos — (i) of bird ; (2) of man — after His. The latter 



about twenty-seven days old 



42. Larvae of common eel ..... 



43. Mendelian inheritance illustrated in wood snail {Helix 



nemoralis) ...... 



44. Gradual transitions between Paludina neumayri (a), the 



oldest form, and Paludina hcernesi (/) — from Neumayr 



45. Structure of Amoeba proteus — after Lucy A. Carter 



46. Life-history of ^wcB&fl ..... 



47. Actinophrys sol (Sun-animalcule) — after Grenacher 



48. Polystomella, megalospheric form, with large central chamber 



(M.) and one nucleus (N.) — after Lister . 



49. Polystomella, microspheric form, with small central chamber 



(c.c.)> numerous nuclei (A^.), bridges of protoplasm 

 between chambers {B.) — after Lister 



50. Paramcecium in longitudinal optical section, and dividing — 



after BUtschli ..... 



51. Conjugation of Paramcecium aurelia — four stages — after 



Maupas ...... 



52. Diagrammatic expression of process of conjugation in Para 



moecium aurelia — after Maupas 



53. Vorticella — after Biitschli .... 



54. Volvox globator — after Klein and Janet 



55. Life-history of Monocystis — after Biitschli 



56. Life-history of Gregarina — after Biitschli 



57. End-to-end union of Gregarines — after Frenzel 



58. Life-history of Coccidium — after Schaudinn 



59. Diagram of Protomyxa aurantiaca — after Haeckel 



60. Formation of shell in a simple Foraminifer — after Dreyer 



61. A pelagic Foraminifer — Hastigerina {Globigerina) murrayi — 



after Brady ....... 



62. The trumpet-shaped ciliated Infusorian, Stentor — after Stein 



