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CHAPTER XX. 



HETKROGENESIS IN LOWER ORGANISMS 



Higher and Lower Organisms. Their Modes of Death. Matter of 

 Aquatic Lower Organisms most prone to undergo Heterogenetic 

 Changes. Dr. Pringsheim's Observations on Algce. Dr. Braxton 

 Hicks on production of Amcebce in Moss-radicles. Development of 

 Amcebee into Ciliata. Mr. Carters observations on Nitella. Pro- 

 duction of Monads. M. Nicolet on Mode of Origin of Amoebce and 

 Actinophrys. Formation of Trichomonas. Its Conversion into 

 other Forms. Mr. Carter on Development of Actinophrys in 

 Spirogyra. Origin of Monads and Amoebse. Development of 

 Pythium in ' resting-spores ' of Algce and in Rotifers. Apftearance 

 of Astasice within Celk of Spirogyra. Other Heterogenetic Changes 

 in Algis and Desmids. Author's Observations on Vaucheria. 

 Mode of Origin of Amcebse and Actinophrys. Heterogenetic 

 Changes in Nitella. Embryonal Spheres. Their various Trans- 

 formations. Origin of complex egg-like Bodies. Transformations 

 of Chlorophyll Corpuscles. Analogous changes previously described. 

 Dr. Braxton Hicks on the Heterogenetic Origin of Glceocapsa. 

 Dr. Gros on Origin of Diatoms and Desmids. Confirmation of his 

 Views. Origin of Desmids from Chlorophyll Corpuscles. Other 

 Modes of Development of Desmids and Diatoms. Modes of Origin 

 ofEuglenee. Interesting Nature of these Organisms. Their various 

 Transformations. Reasons why Algoe and allied Organisms give 

 birth to such varied Products. Bearing of Facts recorded upon 

 Zoological and Botanical Classifications. 



W 



E pass now to a consideration of the lietero- 

 genetic processes which occur in much lower 

 forms of life. And it should be borne in mind when 

 studying the changes that take place in the proto- 



VOL. II. 



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