INDEX 



1513 



reproductive functions, 455 

 reproductive glands, grafting, 300 

 reproductive maturity, 464 

 reptiles, 93 

 respiration, 317 



during hibernation, 61 



in plants, 305 

 respiratory quotient, 339 

 responses, 660 



reticulo-endothelial system, 43S 

 retina — sensitiveness of, 245 

 reversion, 972 

 Rhodesian man, 1154 

 rhythmic behaviour, 68 

 rhythmic behaviour, light effects on, 



68 

 rhythmicity of impulse, 627 

 rhythm in life, 66 

 rhythms, enregistered, 627 

 risks and rewards, 1260 

 rock-record, 877 



Roman snail, low vitality of, 58, 59 

 root — 



climbers, 168 



parasites, 181, 182 

 Rowett Institute, 331 

 rudimentary structures, 921 

 ruminants, cud-chewing, 1074 

 rustic thought, 1388 



Salamander, 59 

 Sanitarian school, 1321 

 sap, ascent of, 312 

 sap-wood, composition of, 311 

 scarf skin, 699 

 science — 



and medicine, 1225 



man's attitude to, 1205 

 scientific achievement illustrated, 



1207 

 scientific knowledge, failure to use, 



1284 

 scientific method, limitations of, 



653 

 Scottish fauna, 1294 

 scramblers, 167 

 sea-elephant, 104 

 seasonal ecology, 53, 55 

 seasonal mass-movement, 69 

 seasons — march of, 52 

 secondary sex-characters, 1022 

 secretions, internal — role of, 491 

 seed-plants, 781 

 seeds — 



dispersal of, 193 



origin of, 873 



segmentation, 732 

 self-preservation, 26, 871 

 seminal fluid, 477 

 senescence, 1267 

 senility, 1267 

 sense of balance, 255 

 sense of direction, 256 

 sex — 



and evolution, 1029 

 and Freud, 543 

 behaviour in birds, 515 

 calls, 510, 1 161 

 characters, criterion, 492 

 determinants, 483 

 evolution, 483 

 illustrations, 485 

 in individual development, 501 

 in spiders, 498 

 characters and specific characters, 



495 

 control of, 537 

 cycle, 518 

 determination, 520 

 determination and nutrition, 532 

 differences, 484 

 differentiation, 521 



epigamic, 521 



progamic, 521 



syngamic, 521 



theories of, 522 

 dimorphism, 507, 565 

 dimorphism, theories of, 487 

 divergence, 1029 

 ethics, 546 

 evils, 1 189 

 evolution, 541, 905 

 instruction, 587 

 linkage, 502 



metabolic theory of, 503 

 origin of, 863 

 parasitism, 507 

 physiological view of, 534 

 proportions, 525 



relationships, extraordinary, 504 

 reversal, 537, 540 

 theory of, 541 

 sexes, changing status of, 1188 

 sexual reproduction fatal, 453 

 sexual reproduction, advantages of, 



453 

 sexual selection, 487, 102 1, 1080 

 shark's face, 1083 

 shelter-associations, 138 

 shying horse, 929 

 Sisymbrium officinale, 22 

 sleep, 264, 408 



