GENERAL INDEX 



169 



tassium in, 129; sodium in, 129; 



sulphate in, 129. 

 Sedimentation constant, of fertili- 



zin, 25. 

 Self-sterility, in Ciona, 138; in 



Forsythia, 51-52. 

 Sense organs, in spermatozoa, 40, 



43- 



Sera, agglutinins in, 26-27. 



Shape changes, in eggs, 18-20, 

 Plate II. 



Shear modulus, of cortex, 95. 



Sodium, in eggs, 84, 129; in sea 

 water, 129. 



Sodium influx, during action poten- 

 tial (nerve), 126, 127. 



Solubility of proteins, 88-89. 



Somatic fertilization, 123. 



Spawning, reciprocal induction of, 

 21-23. 



Specificity, 52, 136-140. 



Sperm density (n), 108-115; effect 

 on cross-fertilization, 138-139. 



head, Ascaridin in, 85 ; rota- 

 tion of, 14-15. 



Lysin, 22, 35-37. Plate IV, 



139- 



— middle-piece, entrance into 

 egg, Plate I, 12-13. 



— tail, entrance into egg, Plate I, 



12-13. 



Sperm-antifertilizin (A. II), 22, 34- 

 35. 37; nature of protein, 34-35- 



Sperm-egg collision frequency (Z), 

 108-110, 138. 



filaments, 7-8, 30. 



interaction rate. See Fertiliza- 

 tion rate. 



interaction time {t), 109-113, 



117, 136. 



Spermatozoa, activation of, 22, 32- 

 34; agglutination of, 21-31, Plate 

 III; chemotaxis of, 13, 22, 39- 

 50; effects of fertilizin on mor- 

 phology of, 7-8, 30, 31; lack of 

 movement in semen, 22, 37-38; 

 live-dead staining, 109 ; morphol- 

 ogy of turning, 41 ; Oj uptake of, 

 32-34; protamines in, 36; ran- 

 dom motion of, 39-42, 45, 108, 



no; repulsive effect of sub- 

 stances on, 47. 



Spherical plasmolysis, loi. 



Stamens, long and short, in For- 

 sythia, 51-54, Plate V. 



Steric hindrance in antigen-anti- 

 body reactions, 31, 140. 



Stiffness, of cortex, 92-94, loi. 



Stigmata of Forsythia, hydrolysing 

 enzymes in, 52. 



Styles, long and short, in Forsythia, 

 51-54, Plate V. 



Sucker. See Cell Elastimeter. 



Sulphatase, in spermatozoa, 89. 



Sulphate, in eggs, 89, 129; in 

 fertilizin, 24-26, 31 ; in sea water, 

 129. 



Supernumerary spermatozoa, be- 

 haviour of, 103-106, 121-123. 



Surface tension, of egg, 92. 



Tanning of vitelline (fertilization) 

 membrane, 9-10, 12, 35, 91, 98, 



IIS- 

 of sona pellucida, 12, 11 4- 115. 



Thiamine, 84. 



Thrombin, production of, in eggs, 

 96. 



Tricarboxylic acid cycle, in eggs, 

 78-79. 



Trypsin, effect on agglutination of 

 red blood cells, 137; effect on 

 combining sites, 137; effect on 

 cortical granules, 10; effect on 

 cortical stiffness, 93, 94; effect 

 on cross-fertilization, 137-138; 

 effect on elevation of fertilization 

 membrane, 88, 93, 121 ; effect on 

 fertilizin, 25 ; effect on incidence 

 of polyspermy, 137; effect on p, 

 137. 



Univalent fertilizin, 28-29. 



Urea, reversal of fertilization by, 



120. 

 Urease, 89. 

 Urechrome, 67. 

 Usnic acid, 85-86. 



