ILLUSTRATIONS 



FIG. PAGE 



1. Forced Position of Larva of the Dragon Fly whose Left Cerebral 



Ganglion is Destroyed 30 



2. Forced Position of Shrimp when Galvanic Current Goes from Head 



to Tail 34 



3. Forced Position of Shrimp when Positive Current Goes from Tail to 



Head 35 



4. Position of Legs of Shrimp when Current Goes Sideways through the 



Animal 37 



5-6. Show Same Effects of Current on the Common Crawfish as Those 



on Shrimp in Figs. 2 and 3 38 



7. Diagram Indicating the Orientation of the Neurons for Flexor and 



Extensor Muscles of the Right and Left Legs 39 



8-9. Diagram Indicating Orientation of Neurons for Flexor and Extensor 



Muscles of Third and Fifth Pairs of Legs 40 



10. Forced Position of Amblystoma Larva Under Influence of Galvanic 



Current Going Through Animal from Head to Tail. . . . 41 



11. Forced Position of Amblystoma Larva When Current Goes from Tail 



to Head 41 



12. Tentacles and Manubrium of Jellyfish Under Influence of Galvanic 



Current ; 42 



13. Strip of Jellyfish Under Influence of Galvanic Current 42 



14. Paramcedum Under Normal Conditions 43 



15. Current Going Through Paramoecium 44 



16. Showing that Positively Heliotropic Animals Will Move from Sun- 



light into Shade if Illumination of Both Eyes Remains the Same.. . . 50 



17. Position of Water Scorpion When Right Eye is Towards the Light . . 53 



18. Positions of Ranatra When Light is in Front and Behind Animal .... 54 



19. Robber Fly Under Normal Conditions 55 



20. Robber Fly with Right Eye Blackened 56 



2 1 . Position of Robber Fly when Lower Halves of Both Eyes are Blackened 57 



22. Position of Robber Fly when Upper Halves of Both Eyes are Blackened 58 



11 



