INDEX AND GLOSSARY. 



247 



Quadruped, animals with four legs, 

 40. 



Radiata, animals whose organs ra- 

 diate from a centre, 23, 27. 



Radius, one of the bones of the 

 arm, 83. 



Reign of fishes ; of man, 235 ; of 

 mammals, 233 ; of reptiles, 238. 



Relation, functions of, 44. 



Reproduction, 131 ; peculiar modes, 

 156. 



Reptiles, number of. 27; reign of, 

 222, 227. 



Respiration, 97, 118. 



Rete mucosum, 129 ; retina, 49. 



Retractile, that may be drawn 

 back, 84. 



Rhizodonts, 20 ; of the trias, 228. 



Rhizopods, 22. 



Rocks, classification of, 215; defi- 

 nition of, 215. 



Rodents, quadrupeds with teeth for 

 gnawing, 107. 



Rotifers, jaws of, 103 ; eggs of, 172. 



Ruminants, quadrupeds which chew 

 the cud, 107. 



Running, 91. 



Rytma Stelleri, 210. 



Salenia, 233. 



Saliferous formation, 218. 



Saliva, 108. 



Salivary glands, 127. 



Salpa, reproduction of, 159 ; motion 

 of, 80. 



Scansores, birds adapted for climb- 

 ing, 20. 



Scaphites, 232. 



Scapula, 82. 



Sclerotic, the principal coat of the 

 eye, 49. 



Scutella, jaws of, 101. 



Sea-anemone. See Actinia. 



Sea-urchin, eye of, 53 ; digestive 

 organs, 98; heart, 117. 



Secondary age, 222, 227. 



Secretions, 97, 126. 



Sedimentary rocks, 215. 



Segment, portion of a circle or 

 sphere. 



Sensation, general, 43, 47. 



Senses, special, 48. 



Sepia, 231. 



Serous, watery, 142. 



Shark, egg of, 133. 



Shoulder-blade, 82. 



Sight, 48. 



Silex, flinty rock. 



Siliceous, made of mnt. 



Silk-worm, metamorphosis of, 176. 



Silurian rocks, lower, 217; upper 

 218. 



Sinuous, bending in and out, 22. 



Siphonophori, 23. 



Siren, 209. 



Skeleton, 74, 77. 



Skin, structure of, 128. 



Smell, 60. 



Species, constancy of. 67; definition 

 of, 17, 159. 



Spinal marrow, 45. 



Spondyli, 233. 



Sponges not animal, 41. 



Spontaneous generation, 171. 



Spores, the germs of sea-weeds 

 ferns, &c., 170. 



Standing, 88. 



Stapes, 57. 



Star-fish, metamorphoses of, 178 

 eye of, 53 ; mode of progression, 

 81 ; reproduction of parts, 126. 



Stigmata, openings in insects for 

 the admission of air, 118. 



Stomach, 97. 



Stratified rocks, 215. 



Stratum, a layer. 



Strobila, 164, 169. 



Structure of the earth's crust, 214 



Sturgeon, compared with white- 

 fish, 180. 



Suctoria, insects taking their food 

 by suction, 21. 



Swimming, 93. 



Sylvia sutoria, nest of, 70. 



Systole, the contraction of the heart 

 to force out the blood, 115. 



Tape-worm, reproduction of, 140. 



Tapir, 204, 234. 



Tarsus, the ancle, 87. 



Taste, 62. 



Teeth, 104. 



Temperate faunas, 198. 



Temporal, relating to the temples, 



Tentacle, the horn-like organs on 

 the head of mollusks, usually 

 bearing the eyes, 52. 



Terebratula, 230. 



Tertiary age, 222, 233. 



Tertiary formation, lower, 218 ; up 

 per, 219. 



