ILLUSTRATIONS 



Dancing Mice sniffing and eating .... Frontispiece 



FIGURE PAGE 



1. Color patterns of dancers. Record blanks .... 4 



2. Double cage, with nest-boxes and water dishes . . 17 



3. Double cages in frame 18 



4. Photographs of dancers climbing (After Zoth) ... 43 



5. Tracks of common mouse (After Alexander and Kreidl) . 44 



6. Tracks of dancer (After Alexander and Kreidl) ... 44 



7. The inner ear of the rabbit (Retzius) . . . . 54 



8. The membranous labyrinth of the ear of the dancer (After 



Rawitz) 56 



9. Same . . . 57 



10. Same ........... 57 



11. Model of the ear of the dancer (After Baginsky) ... 58 



12. Ear of the dancer (After Kishi) 66 



13. Ear of the dancer (After Kishi) . 67 



14. Discrimination box 92 



1 5 . Ground plan of discrimination box 93 



1 6. Nendel's gray papers 115 



17. Weber's law apparatus 119 



18. Food-box apparatus 134 



19. Waugh's food-box apparatus 135 



20. Color discrimination apparatus . . . . '. - 1 53 



21. Ground plan of color discrimination apparatus . . .154 



22. Cards for form discrimination 182 



23. LabyrinthB .184 



24. Labyrinth B on electric wires 188 



25. Labyrinth A 211 



26. Curves of habit formation for labyrinth B . . . .217 



27. Plan of labyrinth C, and path records . . . .219 



28. Labyrinth D 222 



29. Curve of learning for white-black discrimination, twenty 



individuals 231 



