12 ILLUSTRATIONS 



FIG. PAGE 



23. Diagram Showing Position of the Flagellum as Seen in a Viscid 



Medium 62 



24. Tube Worms in Aquarium 63 



25. Same Animals After Position of Aquarium was Reversed 64 



26. Polyps of Eudendrium all Growing Towards Source of Light 66 



27. Fly with Right Eye Blackened 72 



28. Diagram of Apparatus Used to Produce Differential Bilateral Light 



Stimulation 76 



29. Diagram to Show Method of Measuring Trails 77 



30. Diagram for Constructing Direction of Motion of Larva' 80 



31. Method for Proving Validity of Bunson-Roscoe Law 90 



32. A Glass Plate 91 



33. Difference in Gathering Places of Animals 96 



34. Method of Determining the Relative Heliotropic Efficiency of Two 



Different Parts of the Spectrum 107 



35. Geotropic Curvature of Stems of Bryophyllum calycinum 120 



36. All Stems were Originally Straight and Suspended Horizontally 121 



37. When the Size of the Leaf is Reduced by Cutting Out Pieces from the 



Middle 120 



38. Effect of Cutting off Lateral Parts of the Leaves 121 



39. Influence of Motion of the Hand on a Swarm of Sticklebacks in an 



Aquarium 132 



40. The Regenerating Polyp of Tubvlaria in Contact with Glass Wall of 



Aquarium 137 



41. Reactions of Chilomonas to a Drop of -5^ per cent. HC1 145 



42. Method of Proving the Paramoecia are not Positive to Acid of Low 



Concentration 146 



