LIST OF ILLUSTRATIONS 



FIG. PAGE 



1 Amoeba 15 



2 Amoeba, fission 18 



3 Quadrula, Hyalosphenia, 



Arcella, and Difflugia . 20 



4 Various forms of Foramin- 



ifera . . 22 



5 Shells of Foraminifera . . . 2^ 



6 Actinophrys 26 



7 Actinosphaerium 27 



8 Various forms of Heliozoa . 29 



9 Lithocircus 31 



10 Actinomma 32 



11 Collozoum 33 



12 Euglena 35 



13 Various forms of Mastigo- 



phora 37 



14 Various forms of Choano- 



flagellata 39 



15 Various forms of Dinoflag- 



ellata 40 



16 Noctiluca 41 



17 Volvox 43 



1 8 Paramoecium 47 



19 Various forms of Ciliata . 49 



20 Various forms of Tenta- 



culifera . 5 1 



21 Various forms of Ciliata . 53 



22 Vorticella 54 



23 Monocystis 56 



FIG. PAGE 



24 Gregarina . 57 



25 Ovum of Sea-urchin ... 60 



26 Maturation and fertilization 



of ovum 6 1 



27 Segmentation of oosperm . 62 



28 Various forms of epithelium 64 



29 Diagram to illustrate struc- 



ture of glands .... 65 



30 Bones of human arm with 



biceps muscle .... 67 



3 1 Viscera of Frog 69 



32 Hydra ... 73 



33 Sycon 77 



34 ,, magnified 78 



35 ,, transverse section . . 80 



35 bis External form of various 



sponges 83 



36 Ascetta 84 



37 Vertical section of Spongilla 85 



38 Skeleton of various sponges 87 



39 Various forms of sponge 



spicules 88 



40 Obelia 93 



41 Nematocysts of Hydra . . 96 



42 Dissection of a medusa . . 98 



43 Development of Laomedea 



and Eudendrium ... 99 



44 Hydra, structure 101 



45 Two Trachylinse .... 102 



