CHAPTER XXII. 



TRANSFORMATIONS OF CILIATED INFUSORIA : MODES OF ORIGIN 

 OF ROTIFERS, TARDIGRADES, AND NEMATOIDS. 



Convertibility of Lower Forms of Life. Similar Convertibility of 

 Ciliated Infusoria. Vorticella into Oxytricha. Oxytricha into 

 Trichoda. Mr. Carter's Observations. Recent Confirmation of 

 these neglected views. Other Developmental Metamorphoses. 

 General Conclusions concerning Ciliated Infusoria. Their ultimate 

 Transformations. 



Origin of Rotifers. Dr. Gros* Observations. Confirmed by Trans- 

 formation of Vorticella into Diglena. Conversion of Actinophrys 

 into embryo of Rotifer. Fate of other large specimens of 

 Actinophrys. Direct Origin of Rotifers from Vegetal Vesicles. 

 Conversion of 'winter-spore' of Volvox into Philodinian Rotifer. 

 Similar Ti ansformations of Euglense or of Moss-sporangia into 

 other Rotifers. Author's Observations on so-called 'winter-eggs' of 

 Hydatina. Their Mode of Formation from aggregations of Chloro- 

 coccus Vesicles and of Euglense. Instances of Synthetic Hetero- 

 genesis. Reproduction amongst Rotifers. Transformation of Acti- 

 nophrys into Planariole, and of Planariole into Tardigrade. Similar 

 Origin of Nematoids. Transformations of Small Rotifers into 

 Nematoids. Direct Origin of Tardigrades and Nematoids from 

 Euglense. Indubitable Nature of these Changes. Author's Obser- 

 vations on Origin of Nematoids. Conversion of ' resting-spore ' of 

 Vaucheria into an embryo Diplogaster. Inexplicable Facts. 

 New Views harmonious with previous Observations. Universal 

 Distribution of Rotifers, Tardigrades, and Nematoids. Failure 

 of the Panspermic Hypothesis. Heterogenetic Origin of other 

 Higher Forms. Unsolved Problems. 



THE facts hitherto recorded concerning the modes 

 of origin of Ciliated Infusoria are of such a 

 nature as to lead us to expect that these varied forms 



