INDEX 



1515 



time — 



biological importance of, 1368 



fourth dimension, 1380 

 tissues — 



culture, 402 



scrapping, 807 

 tools — 



flaked, 11 70 



smooth-wrought, 11 70 

 tongue — biology of, 259 ^ 



tongues of mammals, 261 

 toothed birds, 882 

 traits in youth, 932 

 trajectory of life, 1260 

 transformations of structures, 925 

 transmissibility of modifications, 1049 

 transmission of training, 1000, 1002 

 transmutation, 1103 

 transpiration current, 310 

 trekking instinct, 1092 

 Triassic Period, 838 

 tropical depression, 12 19 

 tropism, 56, 322, 628 



reversal of, 628 

 Turbellarian worm, 58 

 twiners, 168 

 twins — 



ordinary, 521 



true, 521 



Ultra-microscope, 370 

 unconditioned reflex, 240 

 unicellular organisms, 856 

 unisexual characters, 489 

 unit characters, 1222 

 unity of science, 1141 

 universities, 1360 

 urban thought, 1388 

 urea, synthesis of, 331 

 utility of courtship, 1026 



Vanished British animals, 892 

 variability, 27, 28, 31, 50 



experiments, 50 

 variation and heredity, 1005, 1093 

 variations, 1009 



emergence of, 1248 



in leaf form, 952 



registration of, 1008 

 vascular plants, morphology of, 678 

 vertebrates, 14 

 vestigial organs, 974 

 viper's poison-apparatus, 968 

 virulent microbes, 862 

 visual limits, 370 



vitalism, 447, 1226 

 vitalism and mechanism, 650 

 vital linkages, 106 

 vitamins, 277 



and light, 279 



kinds of, 278, 342 

 viviparity, 793 



prolonged. 793 



Wallace, 1460 

 waltzing mouse, 1246 

 wandering of the poles, 889 

 war — 



and struggle for existence, 131 4 



condemned, 131 1 



effect on race, 1312, 1319 

 warfare, ancient and modern, 131 3 

 warning colours, 418 

 wasps — 



primitive, 1085 



solitary, 1087 

 weeds — spread of, 1043 

 Weismann's theory, 800 

 well-packed bodies, 1070 

 whales, 224 

 whirligig beetle, 12 

 whitlow-grass, 28 

 wild cats, 895 



winged insects — primitive, 878 

 wings, origin of, 878 

 winter-sleepers, 52, 60 

 woman — 



as inventor, 1 186 



in early progress, 1183 



in medical schools, 576 



qualities, 571 

 womanhood, types of, 579 

 Woodcraft Chivalry, 1453 

 work-experience, 1408 

 v/orld — 



deep-sea, 84 



environment, changing, 902 

 world's population — 



increase, 1268 



maximum, 1270 



X-element in ovum, 530 

 Yeast-plants, 360 



Zoological course for arts and science 

 students, 1471 



Zoological Qourse for medical stu- 

 dents, 1470 



zygote, 451 



