TABLE OF CONTENTS 



PART I 



I. The Heliotropism of Animals and its Identity with 



the Heliotropism of Plants - 1 



II. Further Investigations on the Heliotropism of Ani- 

 mals and its Identity with the Heliotropism of 

 Plants - 89 



III. On Instinct and Will in Animals 107 



IV. Heteromorphosis 115 

 V. Geotropism in Animals 176 



VI. Organization and Growth - 191 



VII. Experiments on Cleavage - 253 



VIII. The Artificial Transformation of Positively Helio- 

 tropic Animals into Negatively Heliotropic and 

 vice versa 265 



IX. On the Development of Fish Embryos with Sup- 

 pressed Circulation 295 



X. On a Simple Method of Producing from One Egg 

 Two or More Embryos Which Are Grown 

 Together 303 



XL On the Relative Sensitiveness of Fish Embryos in 

 Various Stages of Development to Lack of Oxygen 

 and Loss of Water 309 



XII. On the Limits of Divisibility of Living Matter 321 



XIII. Remarks on Regeneration 338 



XIV. Contributions to the Brain Physiology of Worms 345 

 XV. The Physiological Effects of Lack of Oxygen - 370 



