LIST OF ILLUSTRATIONS 



FIG. PAGE 



1 Earthworm, Lumbricus terrestris .... 4 



2 Setae of .... 5 



3 Section of .... 8 



4 Internal organs of Lumbricus terrestris . . . 16 



5 Leech, Hirudo medicinalis 27 



6 Internal organs of Hirudo medicinalis ... 28 



7 Internal organs and limbs of Crayfish ... 50 

 Plan of gastric ossicles of Crayfish .... 54 



8, 9, 10, 11, 12 Diagrams of Kreidl's experiments on 



statocysts of Palcemon 61 64 



13 Cockroach, Periplaneta orientalis, dorsal view . 73 



14 side view . . 73 

 15, 16 Front leg and antenna comb of Wasp, Vespa 



germanica ........ 77 



17 Mouth-appendages of Periplaneta . . 81 



18 The internal organs of .... 83 



19 The metamorphosis of a Dragonfly . . . 108, 109 



20 Wings of Dragonflies 113 



21, 22 Hind wing of Wasp .... 126 



23 Stridulating organ of Mosquito . . . .133 



24 Sting of Wasp, Vespa germanica . . . . 135 



25 Section of sting, ..... 136 



26 Tip of sting-needle of Vespa germanica . . . 138 



27 Nest of Wasp at an early stage ... 142 



28 a late 147 



29 Right valve of Anodonta cygnea .... 165 



