602 
INDEX. 
Birds, Mammalia, and Insects, 308 ; 
small amount of, in cold-blooded ani¬ 
mals, 309, 310; no special provision 
for in lowest, 311; uses of cilia in, 
319, 329; an excreting process, 345, 
346; subservient to maintenance of 
heat, 412—414; in embryo, 760, 761. 
Respiratory apparatus of Annelida, 314 ; 
of aquatic Insects, 315; of Crustacea, 
315 ; of Moliusca, 316, 320; of Fishes, 
317, 318, 324; of Myriapoda, 320; of 
Insects, 321—322; of Arachnida, 323; 
of Reptiles, 325; of Birds, 326, 327; 
of Mammals, 328—333; of embryo, 
760, 761. 
- movements, 331—334, 340— 
342. 
- surface, extension of, 312; pro¬ 
longation of, externally, into gills, 313; 
internally into lungs, 313. 
- system of nerves, in Articu- 
lata, 446; in Moliusca, 437, 438; in 
Vertebrata, 450. 
Rete mucosum, 38. 
Retina, 535; yellow spot of, 554; in¬ 
sensible spot of, 554. 
Rhizopods, 129 ; substance of, 64. 
Rhythmical movements, 578, 581. 
Ribs, 633. 
Rodentia, teeth of, 177. 
Rooks, benefit of, 148. 
Rotifera , 105; reproduction of, 750; 
drying up of, 66. 
Ruminating Animals, stomach of, 198; 
foot of, 652. 
Running, act of, 660. 
S. 
Saccharine aliments, 153 ; destination of, 
155—157, 162; conversion of, into olea¬ 
ginous, 156. 
Sacrum, 624, 645. 
Salamander, 732. 
Saliva, secretion of, 190; union of with 
food, 191. 
Salpa, reproduction of, 728. 
Salt, use of, 166, 167. 
Sandhopper, 100. 
Sanguification, 222—224. 
Sarcode, 128. 
Saunderson, case of, 496. 
Scapula, 634, 635, 637. 
Sclerotic coat, 533. 
Scurvy, 165. 
Seal, 664, 665. 
Sebaceous follicles, 38, 375. 
Secretion, general nature of, 245; act 
of, performed by cells, 42, 354; distin¬ 
guished from excretion, 352 ; influence 
of mind upon, 353; transference of, 
361. 
Secreting follicles, 355, 356. 
- membranes, 355. 
- tubes, 357, 358. 
Segmentation of yolk, 736, 756. 
Semicircular canals, 518, 520. 
Semilunar valves, 273. 
Sensation , 432,486 ; organs of, 9 ; general, 
487 ; special, 488, 489 ; dependent on 
supply of blood, 63, 487; modes of 
exciting, 487, 488. 
Sensori-motor actions, 430. 
Sensorium, 429, 486. 
Sensory ganglia, 452; functions of, 475— 
479. 
Serous membranes, structure of, 28; 
arrangement of, 43. 
Serpents, 85, 203; lung of, 325; verte¬ 
bral column of, 629. 
Serpula, 314. 
Serum of blood, 238. 
Shark, teeth of, 188; brain of, 453. 
Shell of Moliusca, 106; of Crustacea, 
99, 170; of Bird’s egg, 755. 
Siamese twins, 729. 
Sighing, 341. 
Sight, sense of, 526—575 (see Vision). 
Silk-worm, voracity of larva of, 141. 
Single Vision, 559. 
Sitting posture, 654, 655. 
Size, visual estimate of, 566. 
Skeleton , position of, in different animals, 
598; internal, of'Vertebrata, 71, 599; 
external, of Articulata, 93, 598; of 
Moliusca, 106, 598; of Radiata, 118', 
124, 127, 131, 132, 598; of Man, 616; 
of Camel, 644; of Bird, 669; of Perch, 
666 ; of Kangaroo, 661; of Seal, 664; 
of Dugong, 664; of Bat, 669; of Ptero- 
dactylus, 669. 
-articulation of pieces of, 601—605. 
Skin, structure of, 36—38; exhalation 
from, 370—374; secretions from, 375; 
sensory papillae of, 37, 490; sensibility 
of, 491—495. 
Skull, bones of, 617—619. 
Sloth, peculiar arterial distribution in, 
264. 
Slug, 106, 107. 
Smell, sense of, 504—509; concerned in 
taste, 501. 
Snail, 106, 107; torpidity of, 67; respi¬ 
ration of, 320; reparative power of, 389. 
Sneezing, 342, 508. 
Sobbing, 341, 
Societies of animals, 706—711. 
Song of animals, 686. 
Soul of Man, 721, 722. 
Sounds, propagated by vibrations, 510— 
512; produced by insects, 676—679; by 
larynx, 682; pitch of, dependent on 
number of vibrations, 523, 682. 
Spatangus, 142. 
Spectacles, choice of, 553. 
Speech, articulate, 686—691. 
Spermatozoids, 731. 
Sperm-cells, of plants, 724; of animals, 
730, 731. 
Spherical aberration, 546, 547. 
Sphinx atropos, sound produced by, 678. 
-- ligustri, nervous system of, 441. 
