INDEX 



Note. — References give the number of the page on which the matter referred to begins. 



Acclimation: in relation to concentra- 

 tion of reagent, 72; in relation to age, 

 82; in relation to temperature, 84; 

 in relation to nutrition, 84, 165; in rela- 

 tion to metabolic rate, 164. See also 

 Susceptibility. 



Age: physiological and morphological, 

 58, 85; criteria of, 85, 178; in relation 

 to time, 87, 97; in relation to hydranth 

 and medusa buds in Pennaria, 151, 

 256; in relation to vegetative repro- 

 duction in plants, 239; in relation to 

 spore formation in plants, 247; of 

 gametes, 349; in relation to matura- 

 tion, 355; in relation to gamete forma- 

 tion, chap, xiv; in relation to partheno- 

 genesis and zygogenesis, 393. See 

 also Age cycle; Rejuvenescence; 

 Senescence. 



Age cycle: occurrence of, 59; in relation 

 to endomixis, 143, 379; in relation to 

 character of nutrition, 169, 179; in 

 relation to reproduction, 178, 239, 247; 

 in relation to other periodicities, 187, 

 192; in relation to spore formation, 

 254; individual and racial, in relation 

 to parthenogenesis and zygogenesis, 

 389; in relation to larval stages and 

 metamorphosis, 420; as one aspect of 

 developmental cycle in world in gen- 

 eral, 465. See also Age; Life cycle; 

 Rejuvenescence; Senescence. 



Alternation of generations: in relation 

 to age cycle in plants, 253; in mosses 

 and ferns,. 254, 366; in seed plants, 254, 

 320, 368. 



Anabolism, 14, 43. 



Anophthalmic form in Planaria doroto- 

 cephala, 112, 223. 



Antheridium: in algae, 316; in mosses 

 and ferns, 318. 



Apical region: metabolic rate in, 202, 

 204; independence of, 210, 213, 215; 

 dominance of, 213, 215, 216; limit of 

 dominance in, among plants,_ 232, 238; 

 physiological condition of, in plants, 

 240, 244. See also Axial gradient; 

 Axis. 



Aplysia limacina, oxygen consumption 

 and carbon-dioxide production during 

 early development in, 411. 



Apogamy: origin of embryo in, 322; in 

 relation to segregation of germ plasm, 

 367; in seed plants, 408. 



Apospory, 322 footnote 2, 408. 



Arbacia punctulata: increase in oxygen 

 consumption of, after fertilization, 

 405; increase in susceptibility of, 

 during early development, 413, 414. 

 See also Sea-urchin. 



Archegonium: of mosses, 316; of fern, 

 338; of Torreya taxifolia, 339. 



Arenicola cristata: period of developmen- 

 tal rejuvenescence in, compared with 

 that of Nereis, 415. 



Arteriosclerosis in relation to senescence, 

 287, 301, 434. 



Ascaris megalocephala: germ path in, 

 324; spermatozoon of, 336; suscepti- 

 bility of gametes of, 351. 



Asterias forbesii, susceptibility of, during 

 early development, 413. See also 

 Starfish. 



Atrophy: senile, 2, 287, 301; from dis- 

 use, 45, 185, 287; difference between, 

 and reduction, 288; of sex organs as 

 condition of senescence, 434. 



Autocatalyst, lecithin as, of growth, 454. 

 See also Autocatalytic reaction. 



Autocatalytic reaction: growth as, 446, 

 452; nature of, 446; curve of, 446; 

 autostatic and autokinetic, 454; leci- 

 thin in, of growth, 454. 



Axial gradient: in Planaria dorotocephala, 

 122, 202; in Stenostomum, 135; in 

 other forms, 203; along polar axis, 

 202, 243; along axis of symmetry, 203; 

 changes in, during development, 203, 

 207; in rate of growth, 204; in animal 

 morphogenesis, 204; origin of, 207; 

 persistence of, through reproduction, 

 209; establishment of, 209; in relation 

 to organic axes, 209; as basis of indi- 

 viduation, 225; maintenance of, 226; 

 of eggs in relation to larval develop- 

 ment, 420; change in, during larval 

 development of Nereis, 421. See also 

 Dominance; Individual; Individua- 

 tion. 



Axiate. See Axis, Individual, Individua- 

 tion. 



469 



