INDEX, 
N.B .—The numbers refer to the paragraphs. 
A. 
Aberration, chromatic, 548, 549; 
spherical, 546, 547; avoided in the 
eye, 549. 
Absorption, nutritive, 171; in Verte- 
hrata, through laeteals, 217; through 
blood-vessels, 218; in Invertebrata, 
225; in non-vascular animals, 225; 
interstitial, performed by lymphatics, 
219; from general surface, by veins, 
220 . 
Abstinence, power of, 140, 141, 152. 
Acalephve, 120 ; luminousness of, 395; 
(see Medusce ). 
Acephalous Mollusca, 111, 113. 
Actinophrys, 130. 
Adipose tissue, 46. 
Aeration.of blood, 253, 303. 
Aerating surface, 311, 312. 
Agamic Reproduction, of Insects, 746, 
747 ; of Entomostraca, 748. 
Air, atmospheric, composition of, 300; 
need of in animals, 207; change of, by 
respiration, 300 — 302; effects of de¬ 
privation of, 297, 298, 310, 338. 
-bladder of Fishes, 324. 
-cells of Birds, 80, 326, 327. 
-tubes and sacs of Insects, 320—322. 
Albinos, 545. 
Albumen, chemical composition of, 13, 
14; use of in blood, 240. 
Albuminous principles of food, 153; des¬ 
tination of, 158—164. 
Aliment, definition of, 132 (see Food). 
Allantois, 760, 761. 
Ammonite, 111. 
Amphibia, 85, 87; circulation in, 287— 
289 ; (see Batrachia and Frog). 
Amphioxus, 53. 
Anabas, respiratory organs of, 318. 
Anastomosis, of arteries, 262—265; of 
nerves, 428. 
Anemone, Sea, 126, 127; reproduction 
of, 726, 739. 
Aneurism, 263. 
Animal Life, functions of, 6, 426, 427; 
nervous system of, 461. 
Animals, distinctive characters of, 6— 
12; dependent on Plants for support, 
144—147. 
Animalcules, structure of, 13, 136, 137; 
heat produced by, 404; movements of, 
577; reproduction of, 135, 725. 
Annelida, general characters of, 104; 
circulation in, 294; respiration of, 
314; luminosity of, 396 ; nervous sys¬ 
tem of, 440; muscular motion of, 597; 
reproduction of, 727, 744. 
Annular ligament, of wrist, 641 ; of 
ancle, 648. 
Anobium, sound of, 677. 
Ant-eaters, 186. 
Antennae of Insects, uses of, 498. 
Anthozoa, 126; development of, 736. 
Ant-lion, instinct of, 697. 
Aorta, 258; valves of, 273. 
Aphides, agamic reproduction of, 727, 
735, 746. 
Aplysia, nervous system of, 438. 
Aquatic animals, respiration in, 298. 
Aqueous humor, 536. 
Arachnida, general characters of, 106; 
circulation in, 293; respiration in, 
323; development of, 751. 
Arachnoid membrane, 43. 
Area pellucida, 757. 
•—— vasculosa, 758. 
Areas, comparative, of arteries, 247. 
Arenicola, 314. 
Areolar tissue, structure and properties 
of, 24—27. 
Argonaut, reproduction of, 753. 
Arm, bones and muscles of, 638—640. 
Arteries, 246 ; comparative areas of, 247; 
walls of, 248; pressure of blood in, 
249 ; protection given to, 250 ; division 
of into capillaries, 251; general distri¬ 
bution of, in Man, 258, 259; in Bird, 
260,261; peculiarities of distribution ©f, 
262, 264, 265; flow of blood through, 
274—276 ; wounds of, 277. 
Articulata, general structure of, 93— 
96; skeleton of, 597—600; nervous 
system of, 440—447; eyes of, 573—575. 
Articulate sounds, 687—691. 
Q Q 
