428 THE AMERICAN NATURALIST. 
much significance, how should we then, with good reasons, 
regard the Rhizopoda, Sporozoa, and Flagellata as so many 
classes? The close resemblance of the phenomena of conju- 
gation in the Ciliata and Suctoria are certainly significant ; but 
we have essentially identical ways of fecundation, etc., of the 
ova in different main groups of Metazoa. In their definite 
formations the Ciliata and Suctoria are as much different from 
each other, or much more so, than, for example, the classes of. 
vertebrates and arthropods. The question seems to be rather 
one of logic : if the Suctoria, in their definite stage, are to be 
considered a degenerated type of Ciliata, they must be ranged 
under the same head, as a subgroup ; if not so, they may well 
rank as a class at the side of the Ciliata. 
NEW PHILADELPHIA, OHIO, 
il, 1898. 
? 
