LIST OF ILLUSTRATIONS. Xlii 



FIG. PAGE 



32. Reconstruction of peripheral nerves in six weeks human em- 



bryo, 17.5 mm. long. From Streeter 56 



33. Three stages in the development of the acustico-lateral system 



in the sea bass. From H. V. Wilson 57 



34. A transverse section through the nasal sac of an embryo of a 



bony fish at about the time of hatching, to show the origin 



of the fibers of the olfactory nerve 61 



35. Two figures representing the formation of unipolar cells in the 



spinal ganglion of the dog embryo. After Van Gehuchten . 62 



36. A median sagittal section of the head of an embryo Ambly- 



stoma punctatum 67 



37. Diagrams representing the development of the buccal cavity, 



hypophysis and nasal pit in Amphioxus and Petromyzon. 

 After Legros 68 



38. A diagram representing the segmentation in a generalized 



vertebrate head 71 



39. Several types of nerve cells from the central and peripheral 



nervous system of vertebrates 78 



40. A unipolar nerve cell from the brain of Carcinas to illustrate 



Bethe's experiment 80 



41. Diagrams intended to show several forms of reflex chains in 



the nervous system of vertebrates 83 



42. A portion of the subepithelial nervous network in the palate 



of the frog. From Prentiss 86 



43. A portion of the nervous network about the walls of a small 



vessel in the palate of the frog. From Prentiss 87 



44. Two ganglion cells of the nervous network in the intestinal 



wall of the leech Pontobdella, showing neurofibrillae pass- 

 ing through the cells. From Bethe after Apathy .... 88 



45. A diagram of the component elements in the spinal cord and 



the nerve roots of a trunk segment, to illustrate the rela- 

 tions of the four functional divisions of the nervous 

 system 97 



46. Diagrams to represent the extent and arrangement of the 



functional divisions in the brain of a selachian 100 



47. A diagram to show the arrangement of the two afferent divis- 



ions in the brain of man 101 



48. General cutaneous endings in the skin of a cyclostome, Lam- 



petra Wilderi 105 



