LIST OF ILLUSTRATIONS xxi 



Figure P^ce 



101-104. Hand and foot of Mycetes seniculus 198, 199 



105-108. Hand and foot of spider monkey 200,201 



109,110. Distal extremities of prehensile tails, Mycetes seniculus and Ateles ater. . . 203 



111. Dorsal surface of brain, Mycetes seniculus 204 



112. Base of brain, Mycetes seniculus 205 



113. Left lateral surface of brain, Mycetes seniculus 206 



114. Right lateral surface of brain, Mycetes seniculus 207 



115. Ventral surface of brain stem, Mycetes seniculus 208 



116. Dorsal surface of brain stem, Mycetes seniculus 209 



117. Mycetes seniculus. Level of the pyramidal decussation 211 



118. Mycetes seniculus. Level of the caudal extremity of the inferior olive 215 



119. Mycetes seniculus. Level through the middle of the inferior olive 217 



120. Mycetes seniculus. Level of the nucleus ambiguus 218 



121. Mycetes seniculus. Level of the cerebellar nuclei 220 



122. Mycetes seniculus. Level of the vestibular nuclei 221 



123. Mycetes seniculus. Level of emergence of sixth nerve 222 



124. Mycetes seniculus. Level through middle of pons Varolii 224 



125. Mycetes seniculus. Level of the inferior colliculus 226 



126. Mycetes seniculus. Level of the superior colliculus 228 



127. Mycetes seniculus. Level of the optic chiasm 229 



128. Mycetes seniculus. Level of the anterior commissure 230 



129. Ventral surface of the gray matter of the brain stem, Mycetes seniculus (color) . 235 



130. Dorsal surface of the gray matter of the brain stem, Mycetes seniculus (color) . . 237 



131. Lateral surface of the gray matter of the brain stem, Mycetes seniculus (color) . 239 



132. Habitat group. Baboon at the water hole 290 



133. Papio cynocephalus (baboon) 291 



134-137. Hand and foot of Papio cynocephalus 292,293 



138. Dorsal surface of brain, Papio cynocephalus 296 



139. Base of brain, Papio cynocephalus 297 



140. Right lateral surface of brain, Papio cynocephalus 298 



141. Left lateral surface of brain, Papio cynocephalus 299 



142. Ventral surface of brain stem, Papio cynocephalus 300 



143. Dorsal surface of brain stem, Papio cynocephalus 301 



144. Baboon. Level of the pyramidal decussation 306 



145. Baboon. Level of caudal extremity of nucleus of Burdach 309 



146. Baboon. Level of the caudal extremity of the inferior olivary nucleus 311 



I4-". Baboon. Level through the middle of the inferior olive 313 



148. Baboon. Level of the vestibular nuclei 316 



149. Baboon. Level of the cerebellar nuclei 319 



150. Baboon. Level of emergent fibers of sixth nerve and caudal fibers of pons. . . 321 



151. Baboon. Level at middle of pons, showing entering trigeminal fibers 324 



152. Baboon. Level of inferior colliculus showing emergence of fourth nerve 326 



153. Baboon. Level of the inferior colliculus 327 



