ILLUSTRATIONS xix 



73. Connecting branch from neuroid to myoneme in Stentor . 203 



74. External fibrillar system of Euplotes patella 207 



75. Stalk of Zoothamnium arbuscula 209 



76. Spasmonem in Zoothamnium 210 



77. Three components of Spironem of ZcoZ/j^i^ww/V/w . . . . 211 



78. Pellicular structure and myonemes in Zoothamn'unn . . . 212 



79. Myonemes of stalk sheath of Vovthella 213 



80. Arrangement of second complex of body fibrils in Epistylis 214 



81. Fibrillar system in Chlamydodon sp 231 



82. Fibrillar system of peristomal region in Conchophthirus 



magna 234 



83. Neuromotor apparatus of D/Ve*/?///! _^iff(^j 235 



84. Neuromotor system in Entodhcus horealis 237 



85. Pellicular fibrils of £;^z/(9r/j//?/(i/V^';;/ ^t/wz/ 239 



86. Optical section of Eupoterion pern'ix 240 



87. Neuromotor system of Haptophrya michiganensis .... 242 



88. Cross section of peripheral region of Balantidium coli . . 245 



89. Diagram of fibrillar system in Nyctotherus hylae .... 249 



90. Spirostomum amhiguum. Diagram of membranelles and 



their intracytoplasmic structures 251 



91. Fibrillar complex of cytostome in Oxytrkha 255 



92. Section through anterior end of Uroleptus halseyi .... 256 



93. Camera sketch of horizontal optical section of Amoeba pro- 



teus 272 



94. Curves showing relation between luminous intensity, reaction 



time, stimulation period, and latent period in Amoeba 



proteus 274 



95. Camera drawings of Amoeba sp. illustrating the response to 



localized illumination 276 



96. Relation between adaptation to light of difi^erent intensities 



and rate of locomotion in Amoeba proteus 278 



97. Camera outlines representing different stages in the process 



of orientation in Amoeba proteus 280 



98. Diagrams showing the position of the flagellum of Euglena 



as seen in a viscid medium 281 



99. Euglena sp. in a crawling state, showing details in the proc- 



ess of orientation 284 



