LIST OF ILLUSTRATIONS. XX111 



FIG. PAGE 



61. A portion of the pituitary membrane, with its arteries and veins inject- 



ed, magnified 15 diameters, . . . . ... 160 



62. Olfactory filaments of the dog, Todd and Bowman, . . . 160 



63. View of the left ear in its natural state, . . . .175 



64. General view of the external, middle, and internal ear, as seen in a 



prepared section, from Scarpa, ..... 175 



65. Anterior view of the external ear, as well as of the meatus auditorius, 



labyrinth, &c., . . . . . . .176 



66. Membrana tympani from the outer (A) and from the inner (B) sides, 177 



67. Ossicles of the left ear articulated, and seen from the outside and below, 178 



68. Labyrinth separated from the solid bone in which it lies embedded, . 180 



69. Cochlea divided parallel with its axis, through the centre of the mo- 



diolus, Breschet, ^ ..... 180 



70. Osseous labyrinth laid open to show especially the membranous 



labyrinth, ........ 181 



71. Auditory nerve, ........ 182 



72. Ampulla of the external semicircular membranous canal, showing the 



mode of termination of its nerve, ..... 182 



73. Auditory nerve taken out of the cochlea, . . . . 183 



74. Papillae of the auditory nerve, on a segment of the spiral lamina of the 



cochlea of a young mouse, ...... 183 



75. Reflection of sound, ....... 186 



76. Vertical section of the head and neck, through the mesial line, to 



show the opening of the Eustachian tube and its relations to the 



pharynx, ........ 194 



77. Reflection and refraction of light, ..... 208 



78. Prism, ......... 210 



79. Double convex lens, ....... 211 



80. Double concave lens, ....... 211 



81. Prismatic spectrum, ....... 212 



82. Aberration of sphericity, ...... 213 



83. Aberration of refrangibility, ...... 214 



84. Front view of the left eye moderately opened, . . . 214 



85. Side view of the same eye, as in fig. 84, showing that the cilia of the 



upper lid are concave upwards, and those of the lower lid concave 



downwards. The general convexity of the eyeball is seen, . . 215 



86. Choroid coat of the eye, ....... 215 



87. Pigmentum nigrum, after Todd and Bowman, .... 216 



88. Retina, . . . . . . . . .216 



89. A. An enlarged plan of the retina, in section. B. The outer surface of 



Jacob's membrane, from Hannover, . . . . . 217 



90. Part of the retina of a frog seen from the outer surface, . . 218 



91. Vertical section of the human retina and hyaloid membrane, after Todd 



and Bowman, ........ 218 



92. Papillae of the retina of the frog, seen from the side turned towards the 



vitreous humour, . ...... 219 



93. Plan of the structures in the fore part of the eye, seen in section, . 219 



94. Posterior segment of transverse section of the globe of the eye seen 



from within, ........ 220 



