xii LIST OF ILLUSTRATIONS. 



FIG. PAGE 



35. Gradual transitions between Paludina neitmayri and 



Pahtdina haernesi (Neumayr) ..... 80 



36. Life history of Amoeba ....... 90 



37. Paramcecium (Btitschli) ....... 91 



38. Conjugation oi Paramcecium aitrelia four stages (Maupas) 92 



39. Diagrammatic expression of process of conjugation in 



Paramcecium anrelia (Maupas) ..... 92 



40. Vorticella (Butschli) ........ 94 



41. Volvox glob at or (Cohn) ....... 96 



42. End-to-end union of Gregarines (Frenzel) .... 98 



43. Life history of Gregarina (Blitschli) 99 



44. Life history of Monocystis (Butschli) 100 



45. Life history of Coccidium (Schaudinn) .... 101 



46. Diagram of Protomyxa aurantiaca (Haeckel) . . . 104 



47. Formation of shell in a simple Foraminifer (Dreyer) . . 105 



48. A Foraminifer (Polystomella) showing shell and pseudopodia 



(Schultze) . 106 



49. A pelagic Foraminifer Hastigerina (Globigcrina] murrayi 



(Brady) 107 



50. Optical section of a Radiolarian (Actinoinina] (Haeckel) . 108 



51. Glossina palpalis, tse-tse fly . . . . .117 



52. Trypanosoma gambiense . . . . . . .118 



53. A colonial flagellate Infusorian Proterospongia haeckelii 



(Saville Kent) 120 



54. Simple sponge (Ascetta priinordialis} (Haeckel) . . .122 



55. A sponge colony . . . . . . . .122 



56. Section of a sponge (F. E. Schulze) 123 



57. Diagram showing types of canal system (Korschelt and 



Heider) 124 



58. Development of Sycandra raphanus (F. E. Schulze) . .128 



59. Diagrammatic representation of development of Oscarella 



lobitlaris (Heider) . . . . . . .129 



60. Young Dicyema (Whitman) and Female Orthonectid (Julin) . 131 



61. Sali ne I la (Frenzel) 131 



62. Diagram of Coelenterate structure . . . . J 35 



63. Colony of Hydractinia on back of a Buccinum shell 



tenanted by a hermit-crab . . . . . .136 



64. Hydra hanging from water-weed (Greene) .... 139 



65. Minute structure of Hydra (T. J. Parker and Jickeli) . . 141 



66. Development of Hydra (Brauer) 143 



67. Surface view of AitreHa (Romanes) ..... 148 



68. Vertical section of Anrelia (Claus) . . . . .149 



69. Diagram of life history of A itrelia (Haeckel) . . I 5 I 



70. Litcernaria (Korotneff) . . . . . . .152 



71. External appearance of Tealia crassicornis . . . .154 



72. Vertical section of a sea-anemone (Andres) . . . 155 



73. Section through sea-anemone (Andres) . . . .156 



74. Diagrammatic section of Zoantharian and of Alcyonarian 



(Chun) 157 



75. The formation of a coral shell (Pfurtscheller) . . . 159 



