TABLE OF CONTENTS 



B. Visual Angles and Fields 288 



Visual Angles, 289 — Position of the Eyes in the Head, 

 290 — Extent of the Binocular Field, 291 — Devices for 

 Enlarging the Binocular Field, 299. 



C. Eye Movements and the Fovea 300 



Kinds of Eye Movements, 300 — Fishes, 303 — Amphibians, 

 305— Reptiles, 305— Birds, and the Visual Trident, 307— 

 Mammals, 310. 



D. Depth- and Solidity-Perception 313 



Clues to Depth and Distance, 313 — Stereopsis in Man, 



315 — The Optic Chiasma in Man and Other Vertebrates, 

 319 — Supposed Value of Partial Decussation, 320 — The 

 Case for Singleness in Animals, 323 — The Evolution of 

 Binocular Vision, 326 — The Nature and Basis of Fusion, 

 331 — The Strange Fate of the Median Eyes, 338 — Sub- 

 stitutes for Binocular Stereopsis, 341. 



E. Movement-Perception 342 



Detection versus Saliency, 343 — Grades of Movement, 345 

 — The Relativity of Movement-Perception, 347 — Motor 

 Factors in Movement-Detection, 348 — Sensory Factors in 

 Movement-Detection, 349 — Adaptation, and Center versus 

 Periphery, 352 — Stroboscopic Movement versus Real Move- 

 ment, 356 — Stroboscopic Vision in Animals, 362 — Men- 

 ner's Theory of the Pecten, 365 — Multiple Optic Pap- 

 illa, 367. 



11. ADAPTATIONS TO MEDIA AND SUBSTRATES . . 368 



A. Aquatic Vision 368 



Definition, 368 — Effect of Water upon the Plan of the 



Eye, 369 — Origin of Intra-Ocular Fluids, 371 — Effects of 

 Water upon Light, 373 — Looking Through the Surface, 

 377 — Streamlining of the Eyeball, 379 — 'Adipose Lids', 

 381— Bottom Fishes, 384 — Cave Fishes, 387— Parasitic 

 Fishes, 390 — Deep-Sea Fishes, 391 — Deep-Sea Larval Eyes, 

 403 — The Common Eel, 405 — Aquatic Amphibia, 407 — 

 Sirenians^CC^Whales, 410— Adaptation to Water Pres- 

 sure?, 415. 



B. Aerial Vision 417 



Changes in Dioptrics, 417— New Extra-Ocular Structures, 

 418 — Adnexa in Amphibia, 418 — The Third Lid and the 

 Fate of the Retractor, 419 — Adnexa in Sphenodon, 420 — 

 Crocodilians, 421 — Turtles, 422 — Lizards, 423 — Snakes, 

 424 — Birds, 424 — Mammals, 425 — Inter-Relations of 

 Globe and Adnexa, 427 — Peculiar Status of the Elasmo- 

 branchs, 428. 



