LIST OF ILLUSTRATIONS 



XV 



FIG. 



63. 

 64. 



65. 



66. 



67. 

 68. 

 69. 

 70. 

 71- 



72. 

 73- 

 74- 



75. 



76. 



77- 



78. 



79- 



80. 

 8i. 



82. 

 83- 



84. 



85. 

 86. 



87. 

 88. 

 89. 

 90. 

 91. 



92. 

 93 



Optical section of a Radiolarian (Actinomma) — after Haeckel 



A Monad Infusorian — after Saville Kent 



Diagram of the structure of Noctiluca . 



Spore -formation in Noctiluca — after Roule 



Glossina palpalis, tsetse fly . . . 



Life-cycle of Plasmodium vivax . 



Trypanosoma gambiense .... 



Colonial Infusorian — Ophrydium sessile — after Saville Kent 

 A colonial flagellate Infusorian — Proterosponia haeckelii — 

 after Saville Kent .... 



Simple sponge (Ascetta primordialis) — after Haeckel 

 A sponge colony ..... 



Sponge spicules ..... 



Section of a sponge — after F. E. Schulze 

 Diagram showing types of canal system — after Korschelt and 

 Heider. The flagellate regions are dark throughout, the 

 mesogloea is dotted, the arrows show the direction of the 

 currents. All the figures represent cross-sections through 

 the wall ...... 



Diagram of sponge structure .... 



Development of Sycandra raphanus — after F. E. Schulze 

 Diagrammatic representation of development of Oscarella 



lobularis — after Heider 

 Diagram of early fixed stage of sponge . 

 A, Young Dicyema — after Whitman. B, Female Orthonectid 



{Rhopalura giardii) — after Julin 

 Salinella — after Frenzel ..... 



Diagram of Coelenterate structure, endoderm darker through 

 out ...... 



Colony of Hydradinia on back of a Buccinum shell tenanted 

 by a hermit-crab ..... 



Diagram of a typical Hydrozoon polyp — after Allman 

 Diagram of stinging-cells or cnidoblasts, the one to the right 

 undischarged ...... 



Hydra hanging from water-weed — after Greene 

 Minute structure of Hydra — after T. J . Parkier and Jickeli 

 Development of Hydra — after Brauer . 

 Bougainvillea — after Allman .... 



Structure of a Swimming-bell or Medusoid, Obelia geniculata 



budded off from a Companularian Hydroid 

 Structure of a Medusoid — after Allman 

 , Surface view of A urelia — from Romanes 



h 



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