LIST OF ILLUSTRATIONS. 



33. Life history of Amceba ..... .86 



34. End-to-end union of Gregarines (Frenzel) . 87 

 35- Life history of Gregarina (Biitschli) ... .88 



36. Life history of Monocystis (Biitschli) . 89 



37. Paramecium (Biitschli) ... 9° 



38. Conjugation of Parametrium aurelia — four stages (Maupas) 9 1 



39. Diagrammatic expression of process of conjugation in 



Paramecium aurelia (Maupas) . 9 1 



40. Vorticella (Biitschli) .... 93 



41. Volvox globator (Cohn) . . . 95 



42. Diagram of Protomyxa auranriaca (Haeckel) . 97 



43. Formation of shell in a simple Foraminifer (Dreyer) . . o& 



44. A Foraminifer (Polystomella) showing shell and pseudopodia 



(Schultze) 99 



45. A pelagic Foraminifer — Hastigeriua (Clobigerina) murrayi 



(Brady) .... .... 100 



46. Optical section of a Radiolarian (Actinomma) (Haeckel) . 101 



47. A colonial flagellate Infusorian — Proterospongia haeckelii 



(Saville Kent) . . 101 



48. Simple sponge {Ascetta primordialis) (Haeckel) . 114 

 48A. A sponge colony (Haeckel) 114 



49. Section of a sponge (F. E. Schulze) . . . .115 



50. Diagram showing types of canal system (Korschelt and 



Heider) . 116 



51. Development of Sycandra raphanus (F. E. Schulze) . . 120 



52. Diagrammatic representation of development of Oscarella 



lobularis (Heider) ....... 121 



53. A. Young Dicyema (Whitman). B. Female Orthonectid 



[Rhopahtra giardii) (Tulin) ... . . 123 



54. Salinella (Frenzel) . . . 123 



55. Diagram of Ccelenterate structure, endoderm darker through- 



out . . 127 



56. Hydra hanging from water-weed (Greene) .... 130 



57. Minute structure of Hydra (T. J. Parker and Jickeli) 133 



58. Development of Hydra (Brauer) . . . 135 



59. Surface view of Aurelia (Romanes) . 140 



60. Vertical section of Attrelia (Claus) . . . 141 



61. Diagram of life history of A urelia (Haeckel) . 142 



62. Lucernaria (Korotneff) ... . 144 



63. External appearance of Tealia crassicornis . . . 145 



64. Vertical section of a sea-anemone (Andres) . . .146 



65. Cross-section through sea-anemone (Andres). . . . 147 



66. Z, Diagrammatic section of Zoantharian ; A, of Alcyonarian 



(Chun) ... 149 



67. Diagram of a gymnoblastic Hydromedusa (Allman) . 150 



68. Diagrammatic figure of a simple Turbellarian . . .157 



69. Diagrammatic figure of part of the structure of a simple 



Turbellarian ..... 157 



70. Structure of liver-fluke (Sommer) . 159 



71. Reproductive organs of liver-fluke (Sommer) 160 



