INDEX 



859 



Frog, 393-422, 448 

 blood pressure, 549 

 circulatory system of, 408 

 development of, 421 

 digestive system of, 404 

 endocrine glands of, 419 

 excretory system of, 411 

 external features of, 394 

 heart, mixing of blood in. 411 

 life cycle of, 420 

 muscles of, 401 

 nervous system of, 415 

 reproduction in, 452 

 reproductive system of, 412 

 respiratory system of, 406 

 skeleton of, 397 

 skin of, 395 



Frontal section, 62 



Fructose, 25, 524 



Fruit flies, 705 



Frustule, l 89 



Fundulus, 839 



Funnel, 259, 260 



Galactose, 524 



Galapagos Islands, 733 



Galen, 8 



Galeopithecus, 842 



Gall bladder, 406, 520 



Galliformes, 841 



Gambusia, 628 



Game birds, 824 



Game habitats. 825 



Gamete, 1 1 4 



Ganglion, 61, 107 



Ganoin, 440 



Gar, 440 



Garden snails, 252 



Gas tension, 88 



Gasterosteus, 839 



Gastric glands. 406. 519 



Gastric pits, 405 



Gastric secretion, control of, 524 



Gastrin, 525 



Gastrodermis. 172, 181 



Gastroliths, 298, 328 



Gastropoda, 834 



general features of, 247 

 Gastrotheca, 452 

 Gastrotricha, 231. 833 

 Gastrovascular system, 81, 186 

 Gastrula, 126 

 Gastrulation, 128, 241. 420 

 Gause's rule. 763 

 Gai'ia, 841 

 Gaviiformes, 841 

 Geckos, 461 

 Geiger counter, 21 



Gel, 17, 31 



Gemmule, 1 79 



Gene, chemical nature of. 683 



Gene-environment interrelations, 689 



Gene mutation, 685 



Gene syinbols, 653 



Genes, 40, 652 



action of, 685 



interactions of. 669 



lethal, 679 



linear order of, 664 



number of, 684 



size of, 684 

 Genetic drift, 703 

 Genetic isolation. 702 

 Genetics, 649-693 



history of, 649 

 Genital pores, 431 

 Genital ridge, 629 

 Genotype. 655 

 Genus. 140, 143 



Geographic distribution of organisms, 733 

 Geographic isolation, 701 

 Geologic time table, 717 

 Geology, 427 



Germ layers, evolution of, 237 

 German measles, 691 

 Giant axons, 106 

 Giant scjuids, 265 

 Giardia, 832 

 Giardia lamb Ha, 806 

 Gibbon, 741 

 Gigantism, 624 

 Gigantopithecus, lAl 

 Gila monster, 459, 460 

 Gill, 87, 247, 248. 263, 448, 529, 559 

 Gill arches, 432 

 Gill bailer, 296 

 Gill bar, 388 

 Gill heart. 263 

 Gill pouches. 430, 518 

 Gill slits, 362, 384, 420, 428, 529 

 Giraffes, 499 



Gizzard, 81, 276, 309, 476 

 Glaciation, 725 

 Glands, tvpes of, 506 

 Glass snake, 459, 460 

 Glass sponge, 175, 176 

 Glaucoma, 579 

 Glenoid fossa, 400 

 Globigerina, 159, 832 

 Globulins, 538 

 Glochidia, 258 

 Glomerular filtration, 562 

 Glomerulosa, 618 

 Glomerulus, 363, 562 

 Glossopharyngeal nerve, 417 

 Glottis, 407, 532 

 Glucagon, 615 

 Glucocorticoids, 618 



