5io 



INDEX 



SKULL 



formation of . . 352 



of ant-eater 168 



of babirusa 232 



of boa constrictor 235 



of chimpanzee 189 



of dog 353, 305-3O7 



of European 195 



of horse 308 



of negro 196 



of orang-outang 188 



of rodent 18O 



Sloth 181, 273, 346 



Slug 131, 267, 92 



Smell 388 



Snail 127, 128, 388, 92, 218 



anatomy of 243 



circulation in 311 



eyes of 391 



fresh-water 1O4 



gullet of 282 



head of 351 



jaw of 218 



locomotion of 371 



nervous system of 378 



teeth of 265, 266 



temperature of 328 



touch of 387 



veligerof 372 



see Gastropoda. 

 Snake .... 154, 155, 354, 422, 429 



circulation in 313 



heads of 135 



locomotion of . 367 



lungs of 281 



poison of 334 



respiration in 326 



teeth of 156, 269 



tongue of 263 



touch of 387 



vertebral column of 352 



Snipe 170 



Solaster 90 



Somite 469 



Songsters 176 



Sorex 183 



Sow bug 104 



Sparrow 176, 160 



Specialization 293 



Species 51,433 



Spelerpes ruber 130 



Sperm cell 408 



Sperm whale 17O 



Sphenoid bone 353 



Sphinx ligustri 333 



Sphinx moth, anatomy of. . . 114,241 

 Spider, 121, 122, 123, 405, 407, 429, 81 , 223 



alimentary canal of 281 



circulation in 311 



eyes of 892 



SPIDER 



fang of 216 



legs of 371 



locomotion of 867 



muscle of 365 



respiration in 322 



silk of 334 



Spinal cord, of am phiox us 117 



of tunicate 116 



Spindle shell 129, 96 



Spinnerets 121,82,223,238 



Spiracles 108, 321, 276 



Splint bone 356, 419 



Sponge, 301, 319, 335, 366, 422, 13, 15, 16 



egg of 405,359 



Spongilla 66 



Spongin 66 



Spoonbill 165 



Sporozoa 61, 7 



Squamata 154 



Squamosal bones 353 



Squash bug 112 



Squid 135,367 



see Cuttlefish. 



Squirrel 191, 328, 374 



flying 370 



Stag 174 



Stapes 390 



Starfish, 



220, 252, 405, 419, 426, 45, 46, 323 



circulation in 310 



digestive process of 295 



eyes of 391 



locomotion of 367, 371 



mouth of 257 



nervous system of .... 378, 33O 



respiration in 319 



skeleton of 338 



stomach of 278 



see Echinodermata. 



Steganopodes 165 



Stentor 68 



Sternum 354, 151 



Stilt 170 



Stomach, coats of 255 



of horse 251 



oflion 253 



of mammals 288 



of porpoise 252 



of ruminant 254 



of tunicate 115 



Stork 165 



Stri* 237 



Striated muscular fibers .... 2O9 



Stridula 399 



Striges 173 



Strix pratincola . 155 



Strombus 129, 1O3 



Strophocheilus 131, 93 



Struggle for existence .... 438, 453 



