VI 



CONTENTS. 



CHAPTER XIX. 



Heterogenesis in Higher Organisms .. 



CHAPTER XX. 



Heterogenesis in Lower Organisms •. 



CHAPTER XXI, 



Transformations of Euglenae and other Organisms: Modes 



of Origin of Ciliated Infusoria .. 



V « 



CHAPTER XXII. 



Transformations of Ciliated Infusoria : Modes of Origin of 



Rotifers, Tardigrades, and Nematoids 



• ■ 



CHAPTER XXIII. 



Individuals, Ephemeromorphs, and Species . . 



CHAPTER XXIV. 



General Considerations : Conclusion .. 



APPENDICES. 



Pages 

 307-368 



369-427 



428-490 



491-540 



.. 54T-604 



. . 605-640 



Appendix A. On some Organisms and other Products of 

 Uncertain Nature met with in boiled Solutions of 

 Ammonic Tartrate, and also in others containing 



Ammonia Silicate . . 



• * 



i-xiv 



Appendix B. On the Living Matter and Organisms con- 

 tained within Crystals of Neutral Ammonic Tartrate xv-xxix 



Appendix C. Comparative Experiments 



Appendix D. On the Variability of the Lower Forms of 



xxx-lii 



Living Matter 



« • 



• • 



* ■ 



liii-cviii 



Appendix E. On the ' Germ-theory' in relation to Epidemic 



and ' Specific ' Contagious Diseases 



* * 



« « 



ix-clv 



cix 



LI 



Fig- 



39' 



Cellular 



F' 



40 

 41 



( 



42 



43 



Globular ( 



Globular 

 Calculi 



Different 1 

 Carbon a 



Peculiar I 

 an old 



44. Different 



magnes' 



45. Evolution 



Tomla- 



46. Bacteria : 



47. Different 



48. Forms i 



Bacter 



49- Developr 



50. Another 



51. Mode of 

 62. Origin 0: 

 63* Devel 



opr 



54' Gradual 



'versioi 

 55. Mode 



oj 



S6. 



Pellici 



Sirupl 



est 



5?. Se 



the p, 

 g^eut 



