298 



SUBJECT INDEX 



Thiurea, cleavage, 166; parthenogenesis, 

 200 



Thorium, and potassium, 209 



Thunder stones, 20 



Time schedule of development, 97-98, 

 Tables 2, 3, 4, Plates III-V 



Torone, 8, 11 



Toxopneustes variegatus, see Lytechinus 

 variegatus 



Transferases, 178 



Triplets, see Compilation, 223 



Tripneustes (Hipponoe) esculentus, white 

 urchin, 9; as food, chardron blanc, "sea 

 eggs," 4, 24; decorates itself, 44; classifica- 

 tion, 65; egg size, 65; first cleavage, 99; 

 chromosomes, 102; many references in 

 Compilation, mostly under Other Species 

 after each topic 



Tube feet, 30, 31; Fig. 6; sex dimorphism, 

 48 



Tubercles, 30 



Twins, triplets, quadruplets, see Compila- 

 tion, 223 



Ultrasonic waves, see Compilation, 223 



Ultraviolet light, see Compilation, 223- 

 224; on animal, 28; on egg, sperm and 

 development, 223-224; viscosity, 225 



Uranium, and potassium, 209 



Uranyl nitrate, cleavage, 166; phosphorus 

 metabolism, 207 



Urchin, term, 3, 4 



Urea, amoeboid eggs, 150, 151, 197; cleav- 

 age, 152, 166; chromatophores, 159; pre- 

 vents fertilization membrane, 179, 181; 

 prevents hyaline layer, 183; partheno- 

 genesis, 200 



Urethane, on sperm, 91; on cleavage 



figure, 104; see Anaesthetics in Com- 

 pilation 



Uses of sea urchins, 22-26 



Usnic acid (antibiotic), cleavage, 166; 

 DNA, 195; on phosphorus metabolism, 

 207 



Variation of skeletal parts, 16 

 Viscosity, see Compilation, 224-226 

 Visible light and Photodynamic action, 



see Compilation, 226-227 

 Vital dyes, see Compilation, 227-228; on 



stratified eggs, 125-126; Table 8 

 Vitamin C (ascorbic acid), cleavage, 166 

 Vitelline membrane, see Compilation, 228- 



230 



Washing eggs (repeatedly), effect on cleav- 

 age, 166; on fertilization membrane, 181 



Weight of egg, 79 



White half-egg, 129, 130, 139-140; Fig. 12; 

 Plates VII, IX; Table 9; properties, 135- 



137 

 White sea urchins, 9, 11, 13 

 Whore's eggs, 5 



X-rays, see Compilation, 230-231 



Yolk granules, see Compilation, 231; im- 

 mature egg, 74; mature egg, 85; cen- 

 trifuged egg, 125; stain, 126; Fig. 12; 

 Plate VII; Table 8 



Yolk quarter-egg, 129, 130, 143; Table 9; 

 Fig. 12; Plate VII 



Zarts, 5 



Zeta potential, 175, 176 



Zincin, 5 



