LIST OF ILLUSTRATIONS. 



Fig. Page 



1. Diagram of a Monodermic Or- 



ganism . . , , . . . . 24 



2. Diagram of a Didermic Or- 



ganism . . . . . . . . 24 



3. Diagram of a Tridermic Organ- 



ism, seen in cross section . . 25 



4. Amoeboid Cells 30 



5. Flagellate Cells , . . . . . 30 



6. Quiescent Cells .. .. .. 31 



7. Types of Epithelium .. .. 32 



8. Connective Tissues . . . . 33 



9. Muscular Tissue . . . . • • 34 



10. Nervous Tissues . . . . • • 35 



11. Diagram of a Cell . . • • 35 



12. Diagram of Mitosis .. ..36 



13. Diagram to illustrate Changes 



of the Nucleus during Cell- 

 division . . . . . . . . 38 



14. Diagram to illustrate Typical 



Conjugation . . . . . . 40 



15. Diagram illustrating Nuclear 



Changes during Sexual Re- 

 production . . . . • • 43 



16. Section of Blastula . . • • 50 



17. Section of Morula . . . • 50 



18. Section of Gastrula .. .. 50 



19. Section of Planula .. .. 51 



20. The Origin of an Organ 



21. The Metamorphosis of the Silk- 



worm Moth 



22. Diagram to illustrate Darwin's 



Theory of Coral Reefs 



23. Protective Resemblance 



24. The Leaf-butterfly of India . . 



25. Hypolimnas Missipus . . 



26. An Example of Protective Re- 



semblance 



27. Amoeba Proteus 85 



28. Amffiba Proteus . . 



29. Paramoecium 



30. Vorticella Nebulifera 



31. Life-History of Gregarina 



32. Types of Foraminiferan Shells 



33. A Heliozoan 



34. A Radiolarian 



35. A Living Foraminiferan 



36. Acineta Tuberosa Expanded 



and Contracted 



37. Sycandra Compressa 



38. Calcareous Triradiate Spicules 



of Sycandra , . . . . . n 



115 

 117 



iiB 

 119 



120 

 121 



Page 

 Transverse Section of a Sycandra 104 

 Amphiblastula Larva of a Cal- 

 careous Sponge . . . . 106 

 Ascetta Primordialis . . . . 107 

 Transverse Section of an Ascon 107 

 Transverse Section of Part of 



the Wall of a Leucon . . 108 



Transverse Section of a Rhagon 109 

 Hydra Viridis with Two Buds 11 1 

 Transverse Section of Hydra .. 112 

 Portion of Body- wall of Hydra 113 

 An Ectoderm Cell, Endoderm 



Cell, and a Nerve Cell .. 114 

 Development of the Nematocyst 



in Cnidoblast Cells 

 Colony of Obelia Geniculata 

 Colony of Obelia Geniculata . . 

 A Medusa of Obelia 

 Lateral View of a Medusa of 



Obelia 



Actinia Mesembryanthemuni . . 

 Transverse Section through the 

 Upper Part of a Young 

 Actinian .. .. .. 122 



Transverse Section through 

 Lower Part of a Young 

 Actinian .. .. .-123 



Alcyonium Digitatum .. ..125 



View of Entire Colony with 



Tentacles Expanded .. 126 



Aurelia Aurita .._ ..^ ..127 



Oral View of Aurelia Aurita _ . . 128 



Median Longitudinal Section 



through the Inter-radial 



Plane of Aurelia .. ..129 



Three Stages in Development 



of Aurelia .. . • .. 130 

 Transverse Section through 

 Upper Part of Scyphula 

 Larva .. .. •• .. 130 



Transverse Section through 

 Lower Part of Scyphula 

 Larva .. .. .. •• 130 



Cydippe Plumosa .. ..131 



Aboral View of Cydippe . . 132 



Adhesive Cells of Cydippe . . 132 

 Types of True Corals .. .-134 



Ventral View of Liver- Fluke . . 137 

 Transverse Section through the 



Liver-Fluke 138 



Structure of Distomum . . •139 



