658 THE AMERICAN NATURALIST. 
through the open ends. Maupas regarded them, together with 
the tentacles of Actinobolus, Ileonema, and Mesodinium, as 
pseudopodia, and thought that through them the ciliates came 
from the Suctoria and the latter from the Rhizopoda. This 
theory of the origin of the Ciliata from Rhizopoda has but an 
historical interest, and it is now very generally if not almost 
universally held that the Suctoria came from the Ciliata ; while 
the tentacled forms of ciliates are merely independent modifi- 
cations for special ends and with no phylogenetic significance. 
A number of minor points suggest the close relation of the 
forms like Actinobolus to the Suctoria, but more careful con- 
sideration leaves little reason to doubt the view that they 
represent merely parallel evolution, being adaptive features for 
special ends. 
