498 PHYSIOLOGY AND MORPHOLOGY OF ANIMALS. 



Motion and locomotion, 227-232. 



Muscle and skeleton, compara- 

 tive morphology and physi- 

 ology of, 232-240. 



Muscles of the eye, 100. 



Muscle, voluntary, 221 ; invol- 

 untary, 223. 



Muscular system, 219-223. 



Myopy, 113. 



Nails, 454. 



Nearsightedness, 113. 



Nerve force versus electricity, 

 64. 



Nerves, 49-65 ; structure of, 56 ; 

 function of, 56. 



Nervous system of man, 29. 



Nervous system of vertebrates, 

 70-83 ; of invertebrates, 84- 

 93 ; of arthropods and anne- 

 lids, 84; of mollusks, 89; of 

 radiates, 92 ; of protozoans, 



93- 

 Number of bones in man, 224. 

 Nutritive functions, 283-287. 



Old-sightedness, 114. 



Optic lobes, 32, 41. 



Organs, rudimentary and use- 

 less, 258. 



Oversightedness, 114. 



Owen's classification of mam- 

 mals, 77. 



Pelagic fauna, 482. 

 Perspective, forms of, 151. 

 Physiology, definition of, 8. 

 Plexuses, 69. 

 Pons Varolii, 32. 

 Presbyopy, 114. 

 Protozoa, structure of, 279. 



Radiata, structure of, 278. 



Relation of plants to animals in 

 regard to creation of animal 

 force, 424. 



Respiration, costal, 363 ; dia- 

 phragmatic or abdominal, 364 ; 

 of mammals, 366 ; of birds, 



366 ; of reptiles, 366 ; of the 

 tortoise, 367 ; of amphibians, 



367 ; of fishes, 368 ; function 

 of, in animal economy, 417 ; 

 chemistry of, 418 ; purpose of 

 combustion in, 419. 



Respiratory organs, 358, 399, 



403, 404, 409- 

 Retina and its functions, 116- 

 122. 



Saliva, composition and use of, 

 294. 



Salivary glands, 292 ; structure 

 of, 293 ; excitation of, 294. 



Scales, 460 ; of reptiles, 461. 



Secretion versus excretion, 416. 



Serial homology of vertebrates, 

 261-266 ; of arthropods and 

 annelids, 267-277. 



Shells, turtle, 462 ; mammalian, 

 463 ; of insects, 463 ; of crusta- 

 ceans, 464 ; of mollusks, 464- 

 466 ; of echinoderms, 466. 



Shoulder girdle, 250. 



Shoulder joint and fore limb, 

 227. 



Sight, sense of, 98. 



Size and distance, judgments of, 



153- 



Skeletal system, 223-232. 



Skin, function of, 435 ; struc- 

 ture of, 436-438 ; comparative 

 morphology and physiology 



