XIV 



LIST OF ILLUSTRATIONS 



22. Relation of amount of COg taken up by crustacean and 



cephalopod blood to CO2 pressure 



23. Ciliary currents on Lamelli branch gill 



24. Crystalline style of bivalve mollusc 



25. Innervation of heart of Palinurus 



26. Heart and nerves of Limulus . 



27. Inhibition of heart-beat of Limulus by electric stimulation of 



brain ..... 



28. Heart of Cephalopod 



29. Circulatory system of Ascidian . 



30. Action of adrenaline on heart of Pecten 



31. Action of adrenaline on crop of Aplysia 



32. 33. Function of pituitary gland in coloration of frogs 



To face page 



34. Excitability to second stimulus in sciatic gastrocnemius of 



frog 



35. Diagram of Adrian's experiment 



36. Diagram illustrating electrical conditions 



resting neurone .... 



37. Excitability by single or double stimuli of 



claw of Astacus .... 



38. Diagram of simple reflex arc 



39. Diagram of pedal ganglion of Razor-shell 



40. Effect of unequal illumination on insect 



41. Genetic segregation 



42. Sex-linked inheritance in Drosophila 



43. Crossing in the gypsy-moth Lymantria 



44. Oxygen consumption of chick embryos 



in excited and 

 abductor nerve of 



