582 



INDEX 



Rotifora, 241. 



Hound worms, see Nemathelminthes. 



Salamanders, 12, 14, 37. 



Saliva, 82. 



Salivary gland, 82, 354. 



Sarcodina, 154, 155, 164, 241. 



Sarcophaga kellyi, 385. 



Say, 322. 



Scale insect, 374, 551. 



Schleiden, 132, 133. 



Schwann, 132, 133, 204. 



Science, 1. 



Scutigera, 340. 



Scyphozoa, scypho-medusse, 241, 274, 



278. 

 Sea anemone, see Actinozoa. 

 Sea urchin, see Echinodermata. 

 Sea walnut, see Ctenophora. 

 Seals, 29, 30, 498. 

 Secretin, 98. 



Secretions, 96 J internal, 97. 

 Sedentaria, 314. 

 Segmentation, 83, 84. 

 Segmentation cavity, 407. 

 Selection, 459, 460, 486, 559. 

 Seminal receptacles, 285, 296, 358. 

 Seminal vesicles, 54, 297, 425. 

 Sense organs, 64, 108, 125, 126; of 

 earthworm, 300, 302; of insects, 

 360, 361, 366; see also Recep- 

 tors. 

 Sensory ceUs, of Hydra, 252, 260, 266; 



see also Receptors. 

 Sensory-neuro-glandular system, 64. 

 Sensory-neuro-muscular system, 64, 



269, 316. 

 Sensory plate, of frog, 410, 413. 

 Septum, 41, 289, 291. 

 Serpula, 314. 

 Serum, blood, 146. 

 Seta, 285, 291. 

 Setigerous sacs, 291. 

 Sex, in Protozoa, 174, 214. 

 Sex-chromosome, 227, 229, 447, 479. 

 Sex-determination, 446. 

 Sex-linked inheritance, 470, 472, 479, 

 482, 483. 



Sexual characters, primary and sec- 

 ondary, 221. 

 Sexual differentiation, 221. 

 Sexual reproduction, 214, 219; see 



also Reproduction. 

 Sexual union, in frog, 55, 400; in 



earthworm, 305. 

 Shark, 37. 

 Sherrington, 114. 

 Shrimp, see Malacostraca. 

 Sight, in locust, 361. 

 Simiida^, 528, 529, 530, 532. 

 Silverfish, 372. 



Single-celled animals, see Protozoa. 

 Sinus venosus, 58. 

 Siphonaptera, 375. 

 Siphonophora, 277. 

 Sipunculoidea, 241, 309, 310. 

 Skate, 37. 



Skeleton, 41, 68, 69, 417. 

 Skin, 40, 95; excretion through, 94. 

 Sleeping sickness, 209. 

 Small intestine, 47; absorption from, 

 88; digestion in, 83; muscular 

 activities of, 84; tissues of wall, 

 149, 150. 

 Smell, sense of, in earthworm, 303; in 



locust, 360. 

 Snail, see Mollusca. 

 Snake, 37, 423. 

 Social sciences, 1. 

 Somatic cells, 199, 216. 

 Somatoplasm, 217, 223. 

 Somites, 282, 322, 334, 344; see also 



Metameres. 

 Sound production, in Amphibia, 20; 



in insects, 364. 

 Spallanzani, 204. 

 Species, 10, 12; inter-relations 



between, 34. 

 Spencer, 554. 



Spermatogenesis, 226, 227; signifi- 

 cance of, 229. 

 Spermatogonia, 227. 

 Spermatozoon, of frog, 54, 223, 230, 



402, 425; structure of, 230, 231. 

 Sphcrrella, 155. 

 Sphecius, 388. 



4 



