CONtENtS Xili 



Echinochrome 1 73 



Electrical properties and effects 175 



Enzymes 177 



Fertilization membrane 178 



Fertilizin and agglutinin 182 



Heat production 182 



Hyaline layer 182 



Hybrids 184 



Hydrogen ion concentration, pH 185 



Infrared light 187 



Jelly layer 187 



Leucocytes 188 



Lipids 189 



Lithium 190 



Magnesium 191 



Mitochondria 192 



Nitrogen 193 



Nuclear division without cell division 193 



Nucleoproteins 194 



Oil (see also lipids) 195 



Osmotic pressure 196 



Oxygen lack and low oxygen tension 197 



Parthenogenesis 198 



Perivisceral fluid 201 



Perivitelline space 202 



Permeability 203 



Phosphorus metabolism 206 



Plasma membrane 208 



Polyspermy 208 



Potassium 209 



Pressure, hydrostatic 210 



Proteins 211 



Radium 212 



Respiration ' 212 



Rhythms of susceptibility 219 



Shell 221 



Sodium 221 



Tension at the surface 222 



Twins, Triplets, Quadruplets 223 



Ultrasonic waves 223 



Ultraviolet light 223 



