TABLE OF CONTENTS xiii 



\\XTII. Experiments on Artificial Parthenogenesis in 

 Annelids (Chsetopteras) and the Nature of the 



Process ot Fertilization 646 



XXXIV. On an Apparently Xe\v Form of Muscular Irrita- 

 bility (Contact-Irritability?) Produced by Solu- 

 tions of Salts (Preferably Sodium Salts) Whose 

 Anions Arc Liable to Form Insoluble Calcium 

 Compounds 692 



XXXV. The Toxic and the Antitoxic Effects of Ions as a 

 Function of Their Valency and Possibly Their 

 Electrical Charge 708 



XXXVI. Maturation, Natural Death, and the Prolongation 

 of the Life of Unfertilized Starfish Eggs 

 (Asterias Forbesii) and Their Significance for 

 the Theory of Fertilization 728 



XXXVII. On the Production and Suppression of Muscular 

 Twitchings and Hypersensitiveness of the Skin 

 by Electrolytes 748 



XXXVIII. On the Methods and Sources of Error in the 



Experiments on Artificial Parthenogenesis 766 



INDEX 773 



